[X86][mingw] Modify the alignment of __m128/__m256/__m512 vector type for mingw

[pengfei]

Summary

This is a follow up patch after D78564 and D108887.

Martin helped to confirm the alignment in GCC mingw is the same as the
size of vector. https://reviews.llvm.org/D108887#inline-1040893

[mstorsjo]

Thanks, this does seem to do the right thing in the testcase you provided.

[pengfei]

Thanks Martin!

clang/lib/CodeGen/TargetInfo.cpp

public:
 
   X86_32ABIInfo(CodeGen::CodeGenTypes &CGT, bool DarwinVectorABI,
                 bool RetSmallStructInRegABI, bool Win32StructABI,
                 unsigned NumRegisterParameters, bool SoftFloatABI)
     : SwiftABIInfo(CGT), IsDarwinVectorABI(DarwinVectorABI),
       IsRetSmallStructInRegABI(RetSmallStructInRegABI),
       IsWin32StructABI(Win32StructABI), IsSoftFloatABI(SoftFloatABI),
       IsMCUABI(CGT.getTarget().getTriple().isOSIAMCU()),
-      IsLinuxABI(CGT.getTarget().getTriple().isOSLinux()),
+      IsLinuxABI(CGT.getTarget().getTriple().isOSLinux() ||
+                 CGT.getTarget().getTriple().isOSCygMing()),
       DefaultNumRegisterParameters(NumRegisterParameters) {}
 
   bool shouldPassIndirectlyForSwift(ArrayRef<llvm::Type*> scalars,
                                     bool asReturnValue) const override {
     // LLVM's x86-32 lowering currently only assigns up to three
     // integer registers and three fp registers.  Oddly, it'll use up to
     // four vector registers for vectors, but those can overlap with the
     // scalar registers.

clang/test/CodeGen/x86_32-align-linux.c

 // RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-gnu -emit-llvm -o - %s | FileCheck %s
 // RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-gnu -target-feature +avx -emit-llvm -o - %s | FileCheck %s
 // RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-gnu -target-feature +avx512f -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-mingw -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-mingw -target-feature +avx -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -w -fblocks -ffreestanding -triple i386-pc-linux-mingw -target-feature +avx512f -emit-llvm -o - %s | FileCheck %s
 
 #include <immintrin.h>
 
 // CHECK-LABEL: define dso_local void @testm128
 // CHECK-LABEL: %argp.cur = load i8*, i8** %args, align 4
 // CHECK-NEXT:  %0 = ptrtoint i8* %argp.cur to i32
 // CHECK-NEXT:  %1 = add i32 %0, 15
 // CHECK-NEXT:  %2 = and i32 %1, -16