Ben Clayton 51be3420b8 tint/writer/glsl: Fix emission of lowest i32 value
GLSL has the same behavior as MSL, in that -2147483648 is parsed as
a unary minus on '2147483648'. 2147483648 overflows an i32, so this
actually gets treated as -0.

Change-Id: Ibebd8b78a8840f18c438ed1d3d24dee486a65816
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/123202
Reviewed-by: Stephen White <senorblanco@chromium.org>
Commit-Queue: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
2023-03-08 21:13:22 +00:00

23 lines
497 B
GLSL

#version 310 es
int tint_mod(int lhs, int rhs) {
int rhs_or_one = (bool(uint((rhs == 0)) | uint(bool(uint((lhs == (-2147483647 - 1))) & uint((rhs == -1))))) ? 1 : rhs);
if (((uint((lhs | rhs_or_one)) & 2147483648u) != 0u)) {
return (lhs - ((lhs / rhs_or_one) * rhs_or_one));
} else {
return (lhs % rhs_or_one);
}
}
void f() {
int a = 1;
int b = 2;
int r = tint_mod(a, b);
}
layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
void main() {
f();
return;
}