[clang] [clang] Implement constexpr bit_cast for vectors (PR #66894)

[Richard Smith via cfe-commits]

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@@ -138,13 +138,14 @@ void g27(void) { // PR8073
 void g28(void) {
   typedef long long v1i64 __attribute((vector_size(8)));
   typedef short v12i16 __attribute((vector_size(24)));
+  typedef unsigned char v24u8 __attribute((vector_size(24)));
   typedef long double v2f80 __attribute((vector_size(24)));
   // CHECK: @g28.a = internal global <1 x i64> <i64 10>
-  // CHECK: @g28.b = internal global <12 x i16> <i16 0, i16 0, i16 0, i16 -32768, i16 16383, i16 0, i16 0, i16 0, i16 0, i16 -32768, i16 16384, i16 0>
+  // CHECK: @g28.b = internal global <24 x i8> <i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 -128, i8 -1, i8 63, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 0, i8 -128, i8 0, i8 64, i8 undef, i8 undef, i8 undef, i8 undef>, align 32
   // CHECK: @g28.c = internal global <2 x x86_fp80> <x86_fp80 0xK3FFF8000000000000000, x86_fp80 0xK40008000000000000000>, align 32
   static v1i64 a = (v1i64)10LL;
-  static v12i16 b = (v12i16)(v2f80){1,2};
-  static v2f80 c = (v2f80)(v12i16){0,0,0,-32768,16383,0,0,0,0,-32768,16384,0};
+  static v24u8 b = (v24u8)(v2f80){1,2};
+  static v2f80 c = (v2f80)(v12i16){0,0,0,-32768,16383,0,0,0,-32768,16384,0,0};
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zygoloid wrote:

I think `c` here was correct before.

https://github.com/llvm/llvm-project/pull/66894