[clang] [Clang] Remove 3-element vector load and store special handling (PR #104661)

[Shilei Tian via cfe-commits]

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@@ -45,7 +45,7 @@ void test3(packedfloat3 *p) {
   *p = (packedfloat3) { 3.2f, 2.3f, 0.1f };
 }
 // CHECK: @test3(
-// CHECK: store <4 x float> {{.*}}, align 4
+// CHECK: store <3 x float> {{.*}}, align 4
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shiltian wrote:

I took another look and this is not only a target option. For example, if it is hlsl, no matter what target it is (spir-v or dxil), vec3 is preserved. I tried to add a function `TargetInfo::getOptimalVectorNumElements(const llvm::FixedVectorType *)`, but it can't cover the language related stuff. If we add an extra argument, like `bool IsHLSL)`, it is too ugly.

https://github.com/llvm/llvm-project/pull/104661