[PATCH] D109203: [X86] Don't clobber EBX in stackprobes

[Elliot Saba via Phabricator via llvm-commits]

staticfloat updated this revision to Diff 370622.
staticfloat added a comment.

Fix test, address review comments


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109203/new/

https://reviews.llvm.org/D109203

Files:
  llvm/lib/Target/X86/X86FrameLowering.cpp
  llvm/test/CodeGen/X86/stack-clash-large.ll


Index: llvm/test/CodeGen/X86/stack-clash-large.ll
===================================================================
--- llvm/test/CodeGen/X86/stack-clash-large.ll
+++ llvm/test/CodeGen/X86/stack-clash-large.ll
@@ -35,12 +35,12 @@
 
 ; CHECK-X86-32-LABEL: foo:
 ; CHECK-X86-32:      # %bb.0:
-; CHECK-X86-32-NEXT:    movl    %esp, %r11d
-; CHECK-X86-32-NEXT:    subl    $69632, %r11d # imm = 0x11000
+; CHECK-X86-32-NEXT:    movl    %esp, %eax
+; CHECK-X86-32-NEXT:    subl    $69632, %eax # imm = 0x11000
 ; CHECK-X86-32-NEXT:    .LBB0_1: # =>This Inner Loop Header: Depth=1
 ; CHECK-X86-32-NEXT:    subl    $4096, %esp # imm = 0x1000
 ; CHECK-X86-32-NEXT:    movl    $0, (%esp)
-; CHECK-X86-32-NEXT:    cmpl    %r11d, %esp
+; CHECK-X86-32-NEXT:    cmpl    %eax, %esp
 ; CHECK-X86-32-NEXT:    jne  .LBB0_1
 ; CHECK-X86-32-NEXT:# %bb.2:
 ; CHECK-X86-32-NEXT:    subl    $2380, %esp
Index: llvm/lib/Target/X86/X86FrameLowering.cpp
===================================================================
--- llvm/lib/Target/X86/X86FrameLowering.cpp
+++ llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -652,7 +652,8 @@
   MF.insert(MBBIter, testMBB);
   MF.insert(MBBIter, tailMBB);
 
-  Register FinalStackProbed = Uses64BitFramePtr ? X86::R11 : X86::R11D;
+  Register FinalStackProbed =
+      Uses64BitFramePtr ? X86::R11 : Is64Bit ? X86::R11D : X86::EAX;
   BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::COPY), FinalStackProbed)
       .addReg(StackPtr)
       .setMIFlag(MachineInstr::FrameSetup);
@@ -1073,7 +1074,8 @@
       MF.insert(MBBIter, bodyMBB);
       MF.insert(MBBIter, footMBB);
       const unsigned MovMIOpc = Is64Bit ? X86::MOV64mi32 : X86::MOV32mi;
-      Register FinalStackProbed = Uses64BitFramePtr ? X86::R11 : X86::R11D;
+      Register FinalStackProbed =
+          Uses64BitFramePtr ? X86::R11 : Is64Bit ? X86::R11D : X86::EAX;
 
       // Setup entry block
       {


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