[llvm] r227667 - ARM: support stack probe size on Windows on ARM

[Saleem Abdulrasool]

Author: compnerd
Date: Fri Jan 30 20:26:37 2015
New Revision: 227667

URL: http://llvm.org/viewvc/llvm-project?rev=227667&view=rev
Log:
ARM: support stack probe size on Windows on ARM

Now that -mstack-probe-size is piped through to the backend via the function
attribute as on Windows x86, honour the value to permit handling of non-default
values for stack probes.  This is needed /Gs with the clang-cl driver or
-mstack-probe-size with the clang driver when targeting Windows on ARM.

Added:
    llvm/trunk/test/CodeGen/ARM/Windows/stack-probe-non-default.ll
Modified:
    llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp?rev=227667&r1=227666&r2=227667&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMFrameLowering.cpp Fri Jan 30 20:26:37 2015
@@ -164,9 +164,13 @@ static int sizeOfSPAdjustment(const Mach
 static bool WindowsRequiresStackProbe(const MachineFunction &MF,
                                       size_t StackSizeInBytes) {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
-  if (MFI->getStackProtectorIndex() > 0)
-    return StackSizeInBytes >= 4080;
-  return StackSizeInBytes >= 4096;
+  const Function *F = MF.getFunction();
+  unsigned StackProbeSize = (MFI->getStackProtectorIndex() > 0) ? 4080 : 4096;
+  if (F->hasFnAttribute("stack-probe-size"))
+    F->getFnAttribute("stack-probe-size")
+        .getValueAsString()
+        .getAsInteger(0, StackProbeSize);
+  return StackSizeInBytes >= StackProbeSize;
 }
 
 namespace {

Added: llvm/trunk/test/CodeGen/ARM/Windows/stack-probe-non-default.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/Windows/stack-probe-non-default.ll?rev=227667&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/ARM/Windows/stack-probe-non-default.ll (added)
+++ llvm/trunk/test/CodeGen/ARM/Windows/stack-probe-non-default.ll Fri Jan 30 20:26:37 2015
@@ -0,0 +1,27 @@
+; RUN: llc -mtriple thumbv7-windows -mcpu cortex-a9 -o - %s \
+; RUN:     | FileCheck %s -check-prefix CHECK-DEFAULT-CODE-MODEL
+
+; RUN: llc -mtriple thumbv7-windows -mcpu cortex-a9 -code-model large -o - %s \
+; RUN:     | FileCheck %s -check-prefix CHECK-LARGE-CODE-MODEL
+
+declare dllimport arm_aapcs_vfpcc void @initialise(i8*)
+
+define dllexport arm_aapcs_vfpcc signext i8 @function(i32 %offset) #0 {
+entry:
+  %buffer = alloca [4096 x i8], align 1
+  %0 = getelementptr inbounds [4096 x i8]* %buffer, i32 0, i32 0
+  call arm_aapcs_vfpcc void @initialise(i8* %0)
+  %arrayidx = getelementptr inbounds [4096 x i8]* %buffer, i32 0, i32 %offset
+  %1 = load i8* %arrayidx, align 1
+  ret i8 %1
+}
+
+attributes #0 = { "stack-probe-size"="8096" }
+
+; CHECK-DEFAULT-CODE-MODEL-NOT: __chkstk
+; CHECK-DEFAULT-CODE-MODEL: sub.w sp, sp, #4096
+
+; CHECK-LARGE-CODE-MODEL-NOT: movw r12, :lower16:__chkstk
+; CHECK-LARGE-CODE-MODEL-NOT: movt r12, :upper16:__chkstk
+; CHECK-LARGE-CODE-MODEL: sub.w sp, sp, #4096
+