From 66301ab9068c5705e5a2bcbf2eaadfb28e8bb084 Mon Sep 17 00:00:00 2001 From: Ellie Hermaszewska Date: Thu, 31 Jul 2025 15:23:13 +0800 Subject: msvc style bitfield packing (#7963) Closes https://github.com/shader-slang/slang/issues/3646 New tests rather than just adding another TEST line to existing tests so that we get the msvc- prefix in the output of slang-test --- .../bitfield/msvc-zero-width.slang | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 tests/language-feature/bitfield/msvc-zero-width.slang (limited to 'tests/language-feature/bitfield/msvc-zero-width.slang') diff --git a/tests/language-feature/bitfield/msvc-zero-width.slang b/tests/language-feature/bitfield/msvc-zero-width.slang new file mode 100644 index 000000000..3363ef066 --- /dev/null +++ b/tests/language-feature/bitfield/msvc-zero-width.slang @@ -0,0 +1,30 @@ +//TEST(compute):COMPARE_COMPUTE(filecheck-buffer=CHECK):-cpu -output-using-type -compile-arg -msvc-style-bitfield-packing + +// MSVC packing with zero-width bitfields +// CHECK: 123 +// CHECK-NEXT: 4567 +// CHECK-NEXT: 1 +// CHECK-NEXT: 0 + +//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer +RWStructuredBuffer outputBuffer; + +struct S { + int foo : 8; // First backing field + int breaker : 0; // Forces new backing field + int bar : 24; // Second backing field +}; + +[numthreads(1, 1, 1)] +void computeMain() +{ + S s; + s.foo = 123; + s.bar = 4567; + s.breaker = 9999; // Zero-width field, assignment has no effect + outputBuffer[0] = s.foo; + outputBuffer[1] = s.bar; + outputBuffer[2] = sizeof(S) == sizeof(int) * 2; // Two backing fields + outputBuffer[3] = s.breaker; // Always returns 0 +} + -- cgit v1.2.3