correct Dst location calculation

Author: folkertdev

llvm/lib/Target/X86/X86ISelLoweringCall.cpp

@@ -2047,7 +2047,6 @@ X86TargetLowering::ByValCopyKind X86TargetLowering::ByValNeedsCopyForTailCall(
   int64_t SrcOffset = MFI.getObjectOffset(SrcFI);
   int64_t DstOffset = MFI.getObjectOffset(DstFI);
 
-
   // If the source is in the local frame, then the copy to the argument
   // memory is always valid.
   bool FixedSrc = MFI.isFixedObjectIndex(SrcFI);
@@ -2232,9 +2231,10 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
 
       // Destination: where this byval should live in the callee’s frame
       // after the tail call.
-      int32_t Offset = VA.getLocMemOffset() + FPDiff + RetAddrSize;
-      SDValue Dst = DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr,
-                                DAG.getIntPtrConstant(Offset, dl));
+      int32_t Offset = VA.getLocMemOffset() + FPDiff ;
+      int Size = VA.getLocVT().getFixedSizeInBits() / 8;
+      int FI = MF.getFrameInfo().CreateFixedObject(Size, Offset, true);
+      SDValue Dst = DAG.getFrameIndex(FI, PtrVT);
 
       ByValCopyKind Copy = ByValNeedsCopyForTailCall(DAG, Src, Dst, Flags);
 

llvm/test/CodeGen/X86/musttail-inalloca.ll

@@ -18,13 +18,15 @@ define dso_local x86_thiscallcc void @methodWithVtorDisp_thunk(ptr %0, ptr inall
 ; CHECK-LABEL: methodWithVtorDisp_thunk:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    pushl %esi
+; CHECK-NEXT:    subl $20, %esp
 ; CHECK-NEXT:    movl %ecx, %esi
 ; CHECK-NEXT:    subl -4(%ecx), %esi
 ; CHECK-NEXT:    pushl {{[0-9]+}}(%esp)
 ; CHECK-NEXT:    pushl $_methodWithVtorDisp_thunk
 ; CHECK-NEXT:    calll ___cyg_profile_func_exit
 ; CHECK-NEXT:    addl $8, %esp
 ; CHECK-NEXT:    movl %esi, %ecx
+; CHECK-NEXT:    addl $20, %esp
 ; CHECK-NEXT:    popl %esi
 ; CHECK-NEXT:    jmp _methodWithVtorDisp # TAILCALL
   %3 = getelementptr inbounds i8, ptr %0, i32 -4

llvm/test/CodeGen/X86/musttail-struct.ll

@@ -1,6 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -x86-asm-syntax=intel | FileCheck %s
-; ; RUN: llc < %s -mtriple=i686-unknown-unknown | FileCheck %s
 
 ; Test correct handling of a musttail call with a byval struct argument.
 
@@ -117,11 +116,8 @@ define void @large_caller_new_value(%twenty_bytes* byval(%twenty_bytes) align 4
 ; CHECK-NEXT:    movabs rcx, 12884901890
 ; CHECK-NEXT:    mov qword ptr [rsp - 12], rcx
 ; CHECK-NEXT:    mov dword ptr [rsp - 4], 4
-; CHECK-NEXT:    mov qword ptr [rsp - 40], rax
-; CHECK-NEXT:    mov qword ptr [rsp - 32], rcx
 ; CHECK-NEXT:    mov qword ptr [rsp + 8], rax
 ; CHECK-NEXT:    mov qword ptr [rsp + 16], rcx
-; CHECK-NEXT:    mov dword ptr [rsp - 24], 4
 ; CHECK-NEXT:    mov dword ptr [rsp + 24], 4
 ; CHECK-NEXT:    jmp large_callee@PLT # TAILCALL
 entry: