[PATCH] D134797: [X86][vectorcall] Make floating-type passed by value to match with MSVC

[Phoebe Wang via Phabricator via cfe-commits]

pengfei added inline comments.


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Comment at: clang/lib/CodeGen/TargetInfo.cpp:1858-1859
     }
-    return getIndirectResult(Ty, /*ByVal=*/false, State);
+    bool ByVal = IsVectorCall && Ty->isFloatingType();
+    return getIndirectResult(Ty, ByVal, State);
   }
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rnk wrote:
> I would try to refactor this so that the vectorcall HFA that can't be passed in SSE regs falls through to the following logic. I suspect that it correctly handles each case that we care about:
> - double: direct
> - vector: indirect for alignment
> - aggregate: indirect for alignment, any HFA will presumably be aligned to more than 32bits
> 
Not sure if I understand it correctly, the HFA is not a floating type, so it won't be affected. Add a test case for it.
MSVC passes it indirectly too. https://gcc.godbolt.org/z/3qf4dTYfv


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Comment at: clang/test/CodeGen/vectorcall.c:157
+// X86-SAME: <4 x float> inreg noundef %xmm5,
+// X86-SAME: double* noundef byval(double) align 4 %0)
 #endif
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rnk wrote:
> Why not pass the double directly? That should be ABI compatible:
> https://gcc.godbolt.org/z/W4rjn63b5
Sorry, I'm not sure what's your mean here. Do you mean I should use your example as the test case? Here the case mocked `vectorcall_indirect_vec`, which I think is intended to check if the type, `inreg` and `byval` etc. are generated correctly.


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  https://reviews.llvm.org/D134797/new/

https://reviews.llvm.org/D134797