diff options
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/tail-call-mutable-memarg.ll | 42 |
2 files changed, 49 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index bcf7874a406..a0fd72dd6a9 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -3983,6 +3983,13 @@ bool MatchingStackOffset(SDValue Arg, unsigned Offset, ISD::ArgFlagsTy Flags, if (Offset != MFI.getObjectOffset(FI)) return false; + // If this is not byval, check that the argument stack object is immutable. + // inalloca and argument copy elision can create mutable argument stack + // objects. Byval objects can be mutated, but a byval call intends to pass the + // mutated memory. + if (!Flags.isByVal() && !MFI.isImmutableObjectIndex(FI)) + return false; + if (VA.getLocVT().getSizeInBits() > Arg.getValueSizeInBits()) { // If the argument location is wider than the argument type, check that any // extension flags match. diff --git a/llvm/test/CodeGen/X86/tail-call-mutable-memarg.ll b/llvm/test/CodeGen/X86/tail-call-mutable-memarg.ll new file mode 100644 index 00000000000..491bbba8c2f --- /dev/null +++ b/llvm/test/CodeGen/X86/tail-call-mutable-memarg.ll @@ -0,0 +1,42 @@ +; RUN: llc < %s | FileCheck %s + +; Make sure we check that forwarded memory arguments are not modified when tail +; calling. inalloca and copy arg elimination make argument slots mutable. + +target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" +target triple = "i386-pc-windows-msvc19.0.24215" + +declare x86_stdcallcc void @tail_std(i32) +declare void @capture(i32*) + +define x86_thiscallcc void @inalloca(i32* %this, i32* inalloca %args) { +entry: + %val = load i32, i32* %args + store i32 0, i32* %args + tail call x86_stdcallcc void @tail_std(i32 %val) + ret void +} + +; CHECK-LABEL: _inalloca: # @inalloca +; CHECK: movl 4(%esp), %[[reg:[^ ]*]] +; CHECK: movl $0, 4(%esp) +; CHECK: pushl %[[reg]] +; CHECK: calll _tail_std@4 +; CHECK: retl $4 + +define x86_stdcallcc void @copy_elide(i32 %arg) { +entry: + %arg.ptr = alloca i32 + store i32 %arg, i32* %arg.ptr + call void @capture(i32* %arg.ptr) + tail call x86_stdcallcc void @tail_std(i32 %arg) + ret void +} + +; CHECK-LABEL: _copy_elide@4: # @copy_elide +; CHECK: leal {{[0-9]+}}(%esp), %[[reg:[^ ]*]] +; CHECK: pushl %[[reg]] +; CHECK: calll _capture +; ... +; CHECK: calll _tail_std@4 +; CHECK: retl $4 |
