From 35c0d4bbe1f3b0abeed74c2ee59927a65daec658 Mon Sep 17 00:00:00 2001
From: dan sinclair <dsinclair@chromium.org>
Date: Tue, 14 Apr 2020 20:32:07 +0000
Subject: [PATCH] [spirv-writer] Add subtracting generation.

This CL adds generation of the OpFSub and OpISub SPIR-V commands from
the subtraction binary expression.

Bug: tint:5
Change-Id: Ia25a855a972057a4cac70d538946e176e0a0e5c3
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/19505
Reviewed-by: David Neto <dneto@google.com>
---
 src/writer/spirv/builder.cc                        |  2 ++
 src/writer/spirv/builder_binary_expression_test.cc | 10 ++++++----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/writer/spirv/builder.cc b/src/writer/spirv/builder.cc
index 8bf9da499b..6ca08d28a4 100644
--- a/src/writer/spirv/builder.cc
+++ b/src/writer/spirv/builder.cc
@@ -619,6 +619,8 @@ uint32_t Builder::GenerateBinaryExpression(ast::BinaryExpression* expr) {
     op = lhs_is_float_or_vec ? spv::Op::OpFOrdNotEqual : spv::Op::OpINotEqual;
   } else if (expr->IsOr()) {
     op = spv::Op::OpBitwiseOr;
+  } else if (expr->IsSubtract()) {
+    op = lhs_is_float_or_vec ? spv::Op::OpFSub : spv::Op::OpISub;
   } else if (expr->IsXor()) {
     op = spv::Op::OpBitwiseXor;
   } else {
diff --git a/src/writer/spirv/builder_binary_expression_test.cc b/src/writer/spirv/builder_binary_expression_test.cc
index 796ec8f1b0..7c5f5bb08f 100644
--- a/src/writer/spirv/builder_binary_expression_test.cc
+++ b/src/writer/spirv/builder_binary_expression_test.cc
@@ -124,6 +124,7 @@ INSTANTIATE_TEST_SUITE_P(
     testing::Values(BinaryData{ast::BinaryOp::kAdd, "OpIAdd"},
                     BinaryData{ast::BinaryOp::kAnd, "OpBitwiseAnd"},
                     BinaryData{ast::BinaryOp::kOr, "OpBitwiseOr"},
+                    BinaryData{ast::BinaryOp::kSubtract, "OpISub"},
                     BinaryData{ast::BinaryOp::kXor, "OpBitwiseXor"}));
 
 using BinaryArithFloatTest = testing::TestWithParam<BinaryData>;
@@ -199,10 +200,11 @@ TEST_P(BinaryArithFloatTest, Vector) {
   EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()),
             "%5 = " + param.name + " %1 %4 %4\n");
 }
-INSTANTIATE_TEST_SUITE_P(BuilderTest,
-                         BinaryArithFloatTest,
-                         testing::Values(BinaryData{ast::BinaryOp::kAdd,
-                                                    "OpFAdd"}));
+INSTANTIATE_TEST_SUITE_P(
+    BuilderTest,
+    BinaryArithFloatTest,
+    testing::Values(BinaryData{ast::BinaryOp::kAdd, "OpFAdd"},
+                    BinaryData{ast::BinaryOp::kSubtract, "OpFSub"}));
 
 using BinaryCompareUnsignedIntegerTest = testing::TestWithParam<BinaryData>;
 TEST_P(BinaryCompareUnsignedIntegerTest, Scalar) {