More closely follow libgcc, which has code after the `ret' instruction to
release the stack segment and reset the stack pointer. Place the code in its own
MBB to make the verifier happy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141859 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index 757cef2..07e0d0e 100644
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -1336,15 +1336,28 @@
if (Is64Bit)
IsNested = HasNestArgument(&MF);
+ // The MOV R10, RAX needs to be in a different block, since the RET we emit in
+ // allocMBB needs to be last (terminating) instruction.
+ MachineBasicBlock *restoreR10MBB = NULL;
+ if (IsNested)
+ restoreR10MBB = MF.CreateMachineBasicBlock();
+
for (MachineBasicBlock::livein_iterator i = prologueMBB.livein_begin(),
e = prologueMBB.livein_end(); i != e; i++) {
allocMBB->addLiveIn(*i);
checkMBB->addLiveIn(*i);
+
+ if (IsNested)
+ restoreR10MBB->addLiveIn(*i);
+ }
+
+ if (IsNested) {
+ allocMBB->addLiveIn(X86::R10);
+ restoreR10MBB->addLiveIn(X86::RAX);
}
if (IsNested)
- allocMBB->addLiveIn(X86::R10);
-
+ MF.push_front(restoreR10MBB);
MF.push_front(allocMBB);
MF.push_front(checkMBB);
@@ -1414,13 +1427,19 @@
if (!Is64Bit)
BuildMI(allocMBB, DL, TII.get(X86::ADD32ri), X86::ESP).addReg(X86::ESP)
.addImm(8);
-
- if (Is64Bit && IsNested)
- BuildMI(allocMBB, DL, TII.get(X86::MOV64rr), X86::R10).addReg(X86::RAX);
-
BuildMI(allocMBB, DL, TII.get(X86::RET));
- allocMBB->addSuccessor(&prologueMBB);
+ if (IsNested)
+ BuildMI(restoreR10MBB, DL, TII.get(X86::MOV64rr), X86::R10)
+ .addReg(X86::RAX);
+
+ if (IsNested) {
+ allocMBB->addSuccessor(restoreR10MBB);
+ restoreR10MBB->addSuccessor(&prologueMBB);
+ } else {
+ allocMBB->addSuccessor(&prologueMBB);
+ }
+
checkMBB->addSuccessor(allocMBB);
checkMBB->addSuccessor(&prologueMBB);
diff --git a/test/CodeGen/X86/segmented-stacks.ll b/test/CodeGen/X86/segmented-stacks.ll
index 37f082c..ecdb00d 100644
--- a/test/CodeGen/X86/segmented-stacks.ll
+++ b/test/CodeGen/X86/segmented-stacks.ll
@@ -81,7 +81,7 @@
; X64-NEXT: movabsq $0, %r10
; X64-NEXT: movabsq $0, %r11
; X64-NEXT: callq __morestack
-; X64-NEXT: movq %rax, %r10
; X64-NEXT: ret
+; X64: movq %rax, %r10
}