[X86] Fix stack probe issue on windows32.

Summary:
On windows if the frame size exceed 4096 bytes, compiler need to
generate a call to _alloca_probe. X86CallFrameOptimization pass
changes the reserved stack size and cause of stack probe function
not be inserted. This patch fix the issue by detecting the call
frame size, if the size exceed 4096 bytes, drop X86CallFrameOptimization.

Reviewers: craig.topper, wxiao3, annita.zhang, rnk, RKSimon

Reviewed By: rnk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65923

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368503 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86CallFrameOptimization.cpp b/lib/Target/X86/X86CallFrameOptimization.cpp
index 4b6f5aba9f0bf3640499c5c8e7adb0e774ed013c..7796945f1c31e4a3c36dccf5b56a101c7705a968 100644 (file)
--- a/lib/Target/X86/X86CallFrameOptimization.cpp
+++ b/lib/Target/X86/X86CallFrameOptimization.cpp
@@ -155,12 +155,22 @@ bool X86CallFrameOptimization::isLegal(MachineFunction &MF) {
   // This is bad, and breaks SP adjustment.
   // So, check that all of the frames in the function are closed inside
   // the same block, and, for good measure, that there are no nested frames.
+  //
+  // If any call allocates more argument stack memory than the stack
+  // probe size, don't do this optimization. Otherwise, this pass
+  // would need to synthesize additional stack probe calls to allocate
+  // memory for arguments.
   unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode();
   unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
+  bool UseStackProbe =
+      !STI->getTargetLowering()->getStackProbeSymbolName(MF).empty();
+  unsigned StackProbeSize = STI->getTargetLowering()->getStackProbeSize(MF);
   for (MachineBasicBlock &BB : MF) {
     bool InsideFrameSequence = false;
     for (MachineInstr &MI : BB) {
       if (MI.getOpcode() == FrameSetupOpcode) {
+        if (TII->getFrameSize(MI) >= StackProbeSize && UseStackProbe)
+          return false;
         if (InsideFrameSequence)
           return false;
         InsideFrameSequence = true;

diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index aff686e9caec5e8f97fd2bc671542221cddbaf4b..47be92e59727f529ffca64a7596a090a4fa8e689 100644 (file)
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -1022,14 +1022,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
       X86FI->getCalleeSavedFrameSize() - TailCallReturnAddrDelta);
 
   bool UseStackProbe = !STI.getTargetLowering()->getStackProbeSymbolName(MF).empty();
-
-  // The default stack probe size is 4096 if the function has no stackprobesize
-  // attribute.
-  unsigned StackProbeSize = 4096;
-  if (Fn.hasFnAttribute("stack-probe-size"))
-    Fn.getFnAttribute("stack-probe-size")
-        .getValueAsString()
-        .getAsInteger(0, StackProbeSize);
+  unsigned StackProbeSize = STI.getTargetLowering()->getStackProbeSize(MF);
 
   // Re-align the stack on 64-bit if the x86-interrupt calling convention is
   // used and an error code was pushed, since the x86-64 ABI requires a 16-byte

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 2d3581fe40326d73ac0f49398ead27c6a6ef57ae..0eb8320d5c542e861dee1001cfdbddf46ffd3852 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -44970,3 +44970,16 @@ X86TargetLowering::getStackProbeSymbolName(MachineFunction &MF) const {
     return Subtarget.isTargetCygMing() ? "___chkstk_ms" : "__chkstk";
   return Subtarget.isTargetCygMing() ? "_alloca" : "_chkstk";
 }
+
+unsigned
+X86TargetLowering::getStackProbeSize(MachineFunction &MF) const {
+  // The default stack probe size is 4096 if the function has no stackprobesize
+  // attribute.
+  unsigned StackProbeSize = 4096;
+  const Function &Fn = MF.getFunction();
+  if (Fn.hasFnAttribute("stack-probe-size"))
+    Fn.getFnAttribute("stack-probe-size")
+        .getValueAsString()
+        .getAsInteger(0, StackProbeSize);
+  return StackProbeSize;
+}

diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h
index 8dc58a188dd2a1d79573f2f0dcc22f980d524a8a..09b0f6bc42b700a710fdf2cb768dd8cb56d71308 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.h
+++ b/lib/Target/X86/X86ISelLowering.h
@@ -1207,6 +1207,8 @@ namespace llvm {
 
     StringRef getStackProbeSymbolName(MachineFunction &MF) const override;
 
+    unsigned getStackProbeSize(MachineFunction &MF) const;
+
     bool hasVectorBlend() const override { return true; }
 
     unsigned getMaxSupportedInterleaveFactor() const override { return 4; }

diff --git a/test/CodeGen/X86/nomovtopush.ll b/test/CodeGen/X86/nomovtopush.ll
new file mode 100644 (file)
index 0000000..f690c23
--- /dev/null
+++ b/test/CodeGen/X86/nomovtopush.ll
@@ -0,0 +1,59 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=i386-pc-windows-msvc | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i386-pc-windows-msvc"
+
+%struct._param_str = type { i32, i32, [4096 x i32], i32 }
+
+@g_d = common dso_local local_unnamed_addr global i32 0, align 4
+@g_c = common dso_local local_unnamed_addr global i32 0, align 4
+@g_b = common dso_local local_unnamed_addr global i32 0, align 4
+@g_a = common dso_local local_unnamed_addr global i32 0, align 4
+@g_param = common dso_local global %struct._param_str zeroinitializer, align 4
+
+; Function Attrs: nounwind
+define dso_local i32 @test() local_unnamed_addr {
+; CHECK-LABEL: test:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    pushl %edi
+; CHECK-NEXT:    pushl %esi
+; CHECK-NEXT:    movl $16396, %eax # imm = 0x400C
+; CHECK-NEXT:    calll __chkstk
+; CHECK-NEXT:    movl _g_d, %eax
+; CHECK-NEXT:    movl _g_c, %ecx
+; CHECK-NEXT:    movl _g_b, %edx
+; CHECK-NEXT:    movl _g_a, %esi
+; CHECK-NEXT:    movl %eax, {{[0-9]+}}(%esp)
+; CHECK-NEXT:    movl %ecx, {{[0-9]+}}(%esp)
+; CHECK-NEXT:    movl %edx, {{[0-9]+}}(%esp)
+; CHECK-NEXT:    movl %esi, (%esp)
+; CHECK-NEXT:    calll _bar
+; CHECK-NEXT:    movl $4099, %ecx # imm = 0x1003
+; CHECK-NEXT:    movl %esp, %edi
+; CHECK-NEXT:    movl $_g_param, %esi
+; CHECK-NEXT:    rep;movsl (%esi), %es:(%edi)
+; CHECK-NEXT:    calll _foo
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    addl $16396, %esp # imm = 0x400C
+; CHECK-NEXT:    popl %esi
+; CHECK-NEXT:    popl %edi
+; CHECK-NEXT:    retl
+entry:
+  %0 = load i32, i32* @g_d, align 4, !tbaa !3
+  %1 = load i32, i32* @g_c, align 4, !tbaa !3
+  %2 = load i32, i32* @g_b, align 4, !tbaa !3
+  %3 = load i32, i32* @g_a, align 4, !tbaa !3
+  %call = tail call i32 @bar(i32 %3, i32 %2, i32 %1, i32 %0) #2
+  tail call void @foo(%struct._param_str* byval nonnull align 4 @g_param) #2
+  ret i32 0
+}
+
+declare dso_local i32 @bar(i32, i32, i32, i32) local_unnamed_addr
+
+declare dso_local void @foo(%struct._param_str* byval align 4) local_unnamed_addr
+
+!3 = !{!4, !4, i64 0}
+!4 = !{!"int", !5, i64 0}
+!5 = !{!"omnipotent char", !6, i64 0}
+!6 = !{!"Simple C/C++ TBAA"}