mirror of https://git.wuffs.org/MWCC
644 lines
25 KiB
C
644 lines
25 KiB
C
#include "compiler/ConstantPropagation.h"
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#include "compiler/Alias.h"
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#include "compiler/BitVectors.h"
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#include "compiler/CompilerTools.h"
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#include "compiler/PCode.h"
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#include "compiler/PCodeInfo.h"
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#include "compiler/RegisterInfo.h"
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#include "compiler/StackFrame.h"
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#include "compiler/UseDefChains.h"
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#include "compiler/objects.h"
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int propagatedconstants;
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static int changed;
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static PCode **defininginstruction;
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static PCode **vrdefininginstruction;
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static void computedefininginstructions(PCodeBlock *block) {
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RegUseOrDef *list;
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PCode *instr;
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int i;
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for (i = 0; i < used_virtual_registers[RegClass_GPR]; i++) {
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instr = NULL;
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for (list = reg_Defs[RegClass_GPR][i]; list; list = list->next) {
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if (bitvectorgetbit(list->id, usedefinfo[block->blockIndex].defvec8)) {
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if (instr == NULL) {
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instr = Defs[list->id].pcode;
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} else {
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instr = NULL;
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break;
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}
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}
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}
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defininginstruction[i] = instr;
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}
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for (i = 0; i < used_virtual_registers[RegClass_VR]; i++) {
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instr = NULL;
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for (list = reg_Defs[RegClass_VR][i]; list; list = list->next) {
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if (bitvectorgetbit(list->id, usedefinfo[block->blockIndex].defvec8)) {
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if (instr == NULL) {
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instr = Defs[list->id].pcode;
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} else {
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instr = NULL;
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break;
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}
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}
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}
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vrdefininginstruction[i] = instr;
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}
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}
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static PCode *isstackoperand(PCodeArg *op, SInt16 *resultValue, SInt16 addend) {
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PCode *instr;
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if ((instr = defininginstruction[op->data.reg.reg]) && instr->op == PC_ADDI) {
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if (
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instr->args[2].kind == PCOp_MEMORY &&
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(instr->args[1].data.reg.reg == _FP_ || instr->args[1].data.reg.reg == _CALLER_SP_) &&
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instr->args[2].data.mem.obj->datatype == DLOCAL
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)
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{
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if (can_add_displ_to_local(instr->args[2].data.mem.obj, addend)) {
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*resultValue = instr->args[2].data.mem.offset;
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return instr;
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} else {
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return NULL;
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}
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} else {
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return NULL;
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}
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} else {
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return NULL;
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}
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}
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static int isconstantoperand(PCodeArg *op, SInt16 *resultValue) {
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PCode *instr;
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if (
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(instr = defininginstruction[op->data.reg.reg]) &&
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instr->op == PC_LI &&
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instr->args[1].kind == PCOp_IMMEDIATE
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)
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{
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*resultValue = instr->args[1].data.imm.value;
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return 1;
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} else {
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return 0;
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}
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}
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static int isuint16constantoperand(PCodeArg *op, SInt16 *resultValue) {
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PCode *instr;
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if (
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(instr = defininginstruction[op->data.reg.reg]) &&
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instr->op == PC_LI &&
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instr->args[1].kind == PCOp_IMMEDIATE &&
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FITS_IN_USHORT(instr->args[1].data.imm.value)
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)
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{
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*resultValue = instr->args[1].data.imm.value;
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return 1;
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} else {
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return 0;
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}
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}
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static int isvectorconstantoperand(PCodeArg *op, SInt16 *resultValue, Opcode *resultNewOp) {
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PCode *instr;
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if (
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(instr = vrdefininginstruction[op->data.reg.reg]) &&
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(instr->op == PC_VSPLTISB || instr->op == PC_VSPLTISH || instr->op == PC_VSPLTISW) &&
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instr->args[1].kind == PCOp_IMMEDIATE
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)
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{
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*resultValue = instr->args[1].data.imm.value;
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*resultNewOp = instr->op;
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return 1;
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} else {
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return 0;
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}
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}
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static int isunsignedloadoperand(PCodeArg *op) {
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PCode *instr;
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if ((instr = defininginstruction[op->data.reg.reg])) {
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if (instr->flags & fPCodeFlag2) {
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if (instr->op >= PC_LHZ && instr->op <= PC_LHZUX)
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return 2;
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if (instr->op >= PC_LBZ && instr->op <= PC_LBZUX)
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return 1;
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} else if (instr->op == PC_RLWINM) {
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int var3 = instr->args[3].data.imm.value;
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int var4 = instr->args[4].data.imm.value;
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if (var4 == 31) {
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if (var3 == 24)
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return 1;
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if (var3 == 16)
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return 2;
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}
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}
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}
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return 0;
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}
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static int ismaskedoperand(PCodeArg *op, UInt32 *resultMask) {
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PCode *instr;
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UInt32 mask;
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if ((instr = defininginstruction[op->data.reg.reg]) && instr->op == PC_RLWINM) {
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if (instr->args[3].data.imm.value <= instr->args[4].data.imm.value) {
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mask =
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((instr->args[3].data.imm.value > 31) ? 0 : (0xFFFFFFFFU >> instr->args[3].data.imm.value)) &
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~(((instr->args[4].data.imm.value + 1) > 31) ? 0 : (0xFFFFFFFFU >> (instr->args[4].data.imm.value + 1)));
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} else {
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mask =
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((instr->args[3].data.imm.value > 31) ? 0 : (0xFFFFFFFFU >> instr->args[3].data.imm.value)) |
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~(((instr->args[4].data.imm.value + 1) > 31) ? 0 : (0xFFFFFFFFU >> (instr->args[4].data.imm.value + 1)));
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}
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*resultMask = mask;
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return 1;
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}
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return 0;
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}
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static int issignedloadoperand(PCodeArg *op) {
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PCode *instr;
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if ((instr = defininginstruction[op->data.reg.reg])) {
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if (instr->flags & fPCodeFlag2) {
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if (instr->op >= PC_LHA && instr->op <= PC_LHAUX)
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return 2;
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} else if (instr->op == PC_EXTSB) {
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return 1;
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} else if (instr->op == PC_EXTSH) {
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return 2;
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}
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}
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return 0;
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}
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static void propagateconstantstoblock(PCodeBlock *block) {
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PCode *instr;
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SInt16 immAddend;
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SInt16 value1;
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SInt16 valueU16;
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Opcode newOpcode;
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SInt16 value2;
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UInt32 mask;
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UInt32 mask2;
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int loadSize;
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PCodeArg *op;
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int i;
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for (instr = block->firstPCode; instr; instr = instr->nextPCode) {
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switch (instr->op) {
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case PC_MR:
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if (isconstantoperand(&instr->args[1], &value1)) {
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = value1;
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instr->args[1].data.imm.obj = NULL;
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propagatedconstants = 1;
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changed = 1;
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}
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break;
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case PC_VMR:
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if (isvectorconstantoperand(&instr->args[1], &value1, &newOpcode)) {
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change_opcode(instr, newOpcode);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = value1;
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instr->args[1].data.imm.obj = NULL;
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propagatedconstants = 1;
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changed = 1;
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}
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break;
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case PC_RLWINM:
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if (
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!(PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000) &&
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instr->args[2].data.imm.value == 0 &&
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instr->args[4].data.imm.value == 31
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)
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{
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if (isconstantoperand(&instr->args[1], &value1)) {
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if (
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(instr->args[3].data.imm.value == 16 && value1 == (value1 & 0x7FFF)) ||
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(instr->args[3].data.imm.value == 24 && value1 == (value1 & 0xFF))
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)
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{
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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break;
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}
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}
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loadSize = isunsignedloadoperand(&instr->args[1]);
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if (
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(loadSize == 2 && instr->args[3].data.imm.value <= 16) ||
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(loadSize == 1 && instr->args[3].data.imm.value <= 24)
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)
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{
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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break;
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}
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if (ismaskedoperand(&instr->args[1], &mask)) {
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if (instr->args[3].data.imm.value <= instr->args[4].data.imm.value) {
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mask2 =
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((instr->args[3].data.imm.value > 31) ? 0 : (0xFFFFFFFFU >> instr->args[3].data.imm.value)) &
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~(((instr->args[4].data.imm.value + 1) > 31) ? 0 : (0xFFFFFFFFU >> (instr->args[4].data.imm.value + 1)));
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} else {
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mask2 =
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((instr->args[3].data.imm.value > 31) ? 0 : (0xFFFFFFFFU >> instr->args[3].data.imm.value)) |
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~(((instr->args[4].data.imm.value + 1) > 31) ? 0 : (0xFFFFFFFFU >> (instr->args[4].data.imm.value + 1)));
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}
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if (mask == (mask & mask2)) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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}
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}
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break;
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case PC_EXTSH:
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if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
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break;
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if (isconstantoperand(&instr->args[1], &value1)) {
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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break;
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}
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loadSize = issignedloadoperand(&instr->args[1]);
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if (loadSize == 1 || loadSize == 2) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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break;
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case PC_EXTSB:
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if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
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break;
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if (
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isconstantoperand(&instr->args[1], &value1) &&
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value1 >= -128 &&
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value1 <= 127
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)
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{
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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break;
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}
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loadSize = issignedloadoperand(&instr->args[1]);
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if (loadSize == 1) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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break;
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case PC_ADDI:
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if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
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break;
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immAddend = instr->args[2].data.imm.value;
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if (
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isconstantoperand(&instr->args[1], &value1) &&
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FITS_IN_SHORT(immAddend + value1)
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)
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{
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = immAddend + value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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break;
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case PC_ADD:
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if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
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break;
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if (isconstantoperand(&instr->args[2], &value1)) {
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if (value1 == 0) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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} else {
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change_opcode(instr, PC_ADDI);
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instr->args[2].kind = PCOp_IMMEDIATE;
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instr->args[2].data.imm.value = value1;
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instr->args[2].data.imm.obj = NULL;
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}
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propagatedconstants = 1;
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changed = 1;
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immAddend = value1;
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}
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if (isconstantoperand(&instr->args[1], &value1)) {
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if (instr->op == PC_ADDI || instr->op == PC_MR) {
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if (FITS_IN_SHORT(immAddend + value1)) {
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = immAddend + value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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} else {
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instr->args[1] = instr->args[2];
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if (value1 == 0) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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} else {
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change_opcode(instr, PC_ADDI);
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instr->args[2].kind = PCOp_IMMEDIATE;
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instr->args[2].data.imm.value = value1;
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instr->args[2].data.imm.obj = NULL;
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}
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propagatedconstants = 1;
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changed = 1;
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}
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}
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if (changed) {
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if (instr->op == PC_MR) {
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PCode *stackInstr;
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if ((stackInstr = isstackoperand(&instr->args[1], &value1, 0))) {
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change_opcode(instr, PC_ADDI);
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instr->flags = stackInstr->flags;
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instr->args[1] = stackInstr->args[1];
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instr->args[2] = stackInstr->args[2];
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change_num_operands(instr, 3);
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propagatedconstants = 1;
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changed = 1;
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}
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} else if (instr->op == PC_ADDI && instr->args[2].kind == PCOp_IMMEDIATE) {
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PCode *stackInstr;
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SInt16 addend = instr->args[2].data.imm.value;
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if ((stackInstr = isstackoperand(&instr->args[1], &value1, addend))) {
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change_opcode(instr, PC_ADDI);
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instr->flags = stackInstr->flags;
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instr->args[1] = stackInstr->args[1];
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instr->args[2] = stackInstr->args[2];
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instr->args[2].data.imm.value = value1 + addend;
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if (instr->flags & (fPCodeFlag2 | fPCodeFlag4 | fPCodeFlag20000 | fPCodeFlag40000))
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instr->alias = make_alias(instr->args[2].data.imm.obj, instr->args[2].data.imm.value, 1);
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propagatedconstants = 1;
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changed = 1;
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}
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}
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}
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break;
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case PC_OR:
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if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
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break;
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value1 = 0;
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immAddend = 0;
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if (isconstantoperand(&instr->args[2], &value1)) {
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if (isuint16constantoperand(&instr->args[2], &valueU16)) {
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if (valueU16 != 0) {
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change_opcode(instr, PC_ORI);
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instr->args[2].kind = PCOp_IMMEDIATE;
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instr->args[2].data.imm.value = valueU16;
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instr->args[2].data.imm.obj = NULL;
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propagatedconstants = 1;
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changed = 1;
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} else {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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value1 = valueU16;
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} else if (value1 == 0) {
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change_opcode(instr, PC_MR);
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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immAddend = value1;
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}
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if (isconstantoperand(&instr->args[1], &value1)) {
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if (instr->op == PC_ORI || instr->op == PC_MR) {
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change_opcode(instr, PC_LI);
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instr->args[1].kind = PCOp_IMMEDIATE;
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instr->args[1].data.imm.value = immAddend | value1;
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instr->args[1].data.imm.obj = NULL;
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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} else if (isuint16constantoperand(&instr->args[1], &valueU16)) {
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if (valueU16 != 0) {
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change_opcode(instr, PC_ORI);
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instr->args[1] = instr->args[2];
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instr->args[2].kind = PCOp_IMMEDIATE;
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instr->args[2].data.imm.value = valueU16;
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instr->args[2].data.imm.obj = NULL;
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propagatedconstants = 1;
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changed = 1;
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} else {
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change_opcode(instr, PC_MR);
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instr->args[1] = instr->args[2];
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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}
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} else if (value1 == 0) {
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change_opcode(instr, PC_MR);
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instr->args[1] = instr->args[2];
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change_num_operands(instr, 2);
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propagatedconstants = 1;
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changed = 1;
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|
}
|
|
}
|
|
break;
|
|
|
|
case PC_SUBF:
|
|
if (PCODE_FLAG_SET_F(instr) & fPCodeFlag20000000)
|
|
break;
|
|
|
|
if (isconstantoperand(&instr->args[1], &value1) && FITS_IN_SHORT(-value1)) {
|
|
if (isconstantoperand(&instr->args[2], &value2) && FITS_IN_SHORT(value2 - value1)) {
|
|
change_opcode(instr, PC_LI);
|
|
instr->args[1].kind = PCOp_IMMEDIATE;
|
|
instr->args[1].data.imm.value = value2 - value1;
|
|
instr->args[1].data.imm.obj = NULL;
|
|
change_num_operands(instr, 2);
|
|
} else if (value1 == 0) {
|
|
change_opcode(instr, PC_MR);
|
|
instr->args[1] = instr->args[2];
|
|
change_num_operands(instr, 2);
|
|
} else {
|
|
change_opcode(instr, PC_ADDI);
|
|
instr->args[1] = instr->args[2];
|
|
instr->args[2].kind = PCOp_IMMEDIATE;
|
|
instr->args[2].data.imm.value = -value1;
|
|
instr->args[2].data.imm.obj = NULL;
|
|
}
|
|
propagatedconstants = 1;
|
|
changed = 1;
|
|
value2 = value1;
|
|
} else if (isconstantoperand(&instr->args[2], &value1) && FITS_IN_SHORT(-value1)) {
|
|
if (value1 == 0) {
|
|
change_opcode(instr, PC_NEG);
|
|
change_num_operands(instr, 2);
|
|
} else {
|
|
instr->flags = opcodeinfo[PC_SUBFIC].flags | (instr->flags & ~opcodeinfo[PC_SUBF].flags);
|
|
change_opcode(instr, PC_SUBFIC);
|
|
instr->args[2].kind = PCOp_IMMEDIATE;
|
|
instr->args[2].data.imm.value = value1;
|
|
instr->args[2].data.imm.obj = NULL;
|
|
instr->args[3].kind = PCOp_REGISTER;
|
|
instr->args[3].arg = RegClass_SPR;
|
|
instr->args[3].data.reg.reg = 0;
|
|
instr->args[3].data.reg.effect = EffectWrite;
|
|
change_num_operands(instr, 4);
|
|
}
|
|
propagatedconstants = 1;
|
|
changed = 1;
|
|
}
|
|
|
|
break;
|
|
|
|
case PC_LBZ:
|
|
case PC_LHZ:
|
|
case PC_LHA:
|
|
case PC_LWZ:
|
|
case PC_STB:
|
|
case PC_STH:
|
|
case PC_STW:
|
|
case PC_LFS:
|
|
case PC_LFD:
|
|
case PC_STFS:
|
|
case PC_STFD:
|
|
if (instr->args[2].kind == PCOp_IMMEDIATE) {
|
|
PCode *stackInstr;
|
|
SInt16 addend = instr->args[2].data.imm.value;
|
|
|
|
if ((stackInstr = isstackoperand(&instr->args[1], &value1, addend))) {
|
|
instr->args[1] = stackInstr->args[1];
|
|
instr->args[2] = stackInstr->args[2];
|
|
instr->args[2].data.imm.value = value1 + addend;
|
|
if (instr->flags & (fPCodeFlag2 | fPCodeFlag4 | fPCodeFlag20000 | fPCodeFlag40000))
|
|
instr->alias = make_alias(instr->args[2].data.imm.obj, instr->args[2].data.imm.value,
|
|
nbytes_loaded_or_stored_by(instr));
|
|
propagatedconstants = 1;
|
|
changed = 1;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case PC_LBZX:
|
|
case PC_LHZX:
|
|
case PC_LHAX:
|
|
case PC_LWZX:
|
|
case PC_STBX:
|
|
case PC_STHX:
|
|
case PC_STWX:
|
|
case PC_LFSX:
|
|
case PC_LFDX:
|
|
case PC_STFSX:
|
|
case PC_STFDX:
|
|
if (isconstantoperand(&instr->args[2], &value1)) {
|
|
instr->op -= 2;
|
|
instr->args[2].kind = PCOp_IMMEDIATE;
|
|
instr->args[2].data.imm.value = value1;
|
|
instr->args[2].data.imm.obj = NULL;
|
|
propagatedconstants = 1;
|
|
changed = 1;
|
|
} else if (isconstantoperand(&instr->args[1], &value1)) {
|
|
instr->op -= 2;
|
|
instr->args[1] = instr->args[2];
|
|
instr->args[2].kind = PCOp_IMMEDIATE;
|
|
instr->args[2].data.imm.value = value1;
|
|
instr->args[2].data.imm.obj = NULL;
|
|
propagatedconstants = 1;
|
|
changed = 1;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
for (i = 0, op = instr->args; i < instr->argCount; i++, op++) {
|
|
if (
|
|
op->kind == PCOp_REGISTER &&
|
|
op->arg == RegClass_GPR &&
|
|
(op->data.reg.effect & EffectWrite)
|
|
)
|
|
{
|
|
defininginstruction[op->data.reg.reg] = instr;
|
|
}
|
|
else if (
|
|
op->kind == PCOp_REGISTER &&
|
|
op->arg == RegClass_VR &&
|
|
(op->data.reg.effect & EffectWrite)
|
|
)
|
|
{
|
|
vrdefininginstruction[op->data.reg.reg] = instr;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void propagateconstants(void) {
|
|
PCodeBlock *block;
|
|
int i;
|
|
|
|
propagatedconstants = 0;
|
|
computeusedefchains(0);
|
|
defininginstruction = galloc(sizeof(PCode *) * used_virtual_registers[RegClass_GPR]);
|
|
vrdefininginstruction = galloc(sizeof(PCode *) * used_virtual_registers[RegClass_VR]);
|
|
|
|
do {
|
|
changed = 0;
|
|
for (i = 0; i < pcblockcount; i++) {
|
|
if ((block = depthfirstordering[i])) {
|
|
computedefininginstructions(block);
|
|
propagateconstantstoblock(block);
|
|
}
|
|
}
|
|
} while (changed);
|
|
|
|
freeoheap();
|
|
}
|