Always reserve space for 8 spilled GPRs. GCC apparently assumes that this
space will be available, even if the callee isn't varargs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28571 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 18e1cba..a021c0e 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -916,18 +916,13 @@
for (unsigned i = 0; i != NumOps; ++i)
NumBytes += MVT::getSizeInBits(Op.getOperand(5+2*i).getValueType())/8;
- // If we are calling what looks like a varargs function on the caller side,
- // there are two cases:
- // 1) The callee uses va_start.
- // 2) The callee doesn't use va_start.
- //
- // In the case of #1, the prolog code will store up to 8 GPR argument
- // registers to the stack, allowing va_start to index over them in memory.
- // Because we cannot tell the difference (on the caller side) between #1/#2,
- // we have to conservatively assume we have #1. As such, make sure we have
- // at least enough stack space for the caller to store the 8 GPRs.
- if (isVarArg && Op.getNumOperands() > 5 && NumBytes < 56)
- NumBytes = 56;
+ // The prolog code of the callee may store up to 8 GPR argument registers to
+ // the stack, allowing va_start to index over them in memory if its varargs.
+ // Because we cannot tell if this is needed on the caller side, we have to
+ // conservatively assume that it is needed. As such, make sure we have at
+ // least enough stack space for the caller to store the 8 GPRs.
+ if (NumBytes < 24+8*4)
+ NumBytes = 24+8*4;
// Adjust the stack pointer for the new arguments...
// These operations are automatically eliminated by the prolog/epilog pass