[llvm] r247348 - [WinEH] Push and pop EBP for 32-bit funclets

[Reid Kleckner via llvm-commits]

Author: rnk
Date: Thu Sep 10 17:00:02 2015
New Revision: 247348

URL: http://llvm.org/viewvc/llvm-project?rev=247348&view=rev
Log:
[WinEH] Push and pop EBP for 32-bit funclets

The Win32 EH runtime caller does not preserve EBP, even though it does
preserve the CSRs (EBX, ESI, EDI) for us. The result was that each
finally funclet call would leave the frame pointer off by 12 bytes.

Modified:
    llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
    llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll
    llvm/trunk/test/CodeGen/X86/win-catchpad.ll
    llvm/trunk/test/CodeGen/X86/win32-seh-cleanupendpad.ll

Modified: llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FrameLowering.cpp?rev=247348&r1=247347&r2=247348&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FrameLowering.cpp Thu Sep 10 17:00:02 2015
@@ -702,6 +702,11 @@ void X86FrameLowering::emitPrologue(Mach
     // Set up the FramePtr and BasePtr physical registers using the address
     // passed as EBP or RDX by the MSVC EH runtime.
     if (STI.is32Bit()) {
+      // PUSH32r %ebp
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
+          .addReg(MachineFramePtr, RegState::Kill)
+          .setMIFlag(MachineInstr::FrameSetup);
+      // Reset EBP / ESI to something good.
       MBBI = restoreWin32EHFrameAndBasePtr(MBB, MBBI, DL);
     } else {
       // FIXME: Add SEH directives.
@@ -715,7 +720,7 @@ void X86FrameLowering::emitPrologue(Mach
         .addReg(RDX)
         .setMIFlag(MachineInstr::FrameSetup);
       // PUSH64r %rbp
-      BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+      BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH64r))
           .addReg(MachineFramePtr, RegState::Kill)
           .setMIFlag(MachineInstr::FrameSetup);
       // MOV64rr %rdx, %rbp
@@ -1066,13 +1071,11 @@ void X86FrameLowering::emitEpilogue(Mach
 
   if (isFuncletReturnInstr(MBBI)) {
     NumBytes = MFI->getMaxCallFrameSize();
+    assert(hasFP(MF) && "win64 EH funclets without FP not yet implemented");
 
-    if (Is64Bit) {
-      assert(hasFP(MF) && "win64 EH funclets without FP not yet implemented");
-      // POP64r %rbp
-      BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
-              MachineFramePtr);
-    }
+    // Pop EBP.
+    BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
+            MachineFramePtr);
   } else if (hasFP(MF)) {
     // Calculate required stack adjustment.
     uint64_t FrameSize = StackSize - SlotSize;

Modified: llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll?rev=247348&r1=247347&r2=247348&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll Thu Sep 10 17:00:02 2015
@@ -73,6 +73,7 @@ catchendblock:
 ; X86: retl
 
 ; X86: [[catch1bb:LBB0_[0-9]+]]: # %catch{{$}}
+; X86: pushl %ebp
 ; X86-NOT: pushl
 ; X86: addl $12, %ebp
 ; X86: subl $16, %esp
@@ -81,7 +82,7 @@ catchendblock:
 ; X86: calll _f
 ; X86: movl $[[contbb]], %eax
 ; X86-NEXT: addl $16, %esp
-; X86-NOT: popl
+; X86-NEXT: popl %ebp
 ; X86-NEXT: retl
 
 ; X86: L__ehtable$try_catch_catch:

Modified: llvm/trunk/test/CodeGen/X86/win-catchpad.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-catchpad.ll?rev=247348&r1=247347&r2=247348&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win-catchpad.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win-catchpad.ll Thu Sep 10 17:00:02 2015
@@ -76,6 +76,7 @@ catchendblock:
 ; X86: retl
 
 ; X86: [[catch1bb:LBB0_[0-9]+]]: # %catch{{$}}
+; X86: pushl %ebp
 ; X86: addl $12, %ebp
 ; X86: subl $8, %esp
 ; X86: movl $1, -{{[0-9]+}}(%ebp)
@@ -85,9 +86,11 @@ catchendblock:
 ; X86: calll _f
 ; X86: movl $[[contbb]], %eax
 ; X86-NEXT: addl $8, %esp
+; X86-NEXT: popl %ebp
 ; X86-NEXT: retl
 
 ; X86: [[catch2bb:LBB0_[0-9]+]]: # %catch.2{{$}}
+; X86: pushl %ebp
 ; X86: addl $12, %ebp
 ; X86: subl $8, %esp
 ; X86: movl $1, -{{[0-9]+}}(%ebp)
@@ -97,6 +100,7 @@ catchendblock:
 ; X86: calll _f
 ; X86: movl $[[contbb]], %eax
 ; X86-NEXT: addl $8, %esp
+; X86-NEXT: popl %ebp
 ; X86-NEXT: retl
 
 ; X86: L__ehtable$try_catch_catch:

Modified: llvm/trunk/test/CodeGen/X86/win32-seh-cleanupendpad.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win32-seh-cleanupendpad.ll?rev=247348&r1=247347&r2=247348&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win32-seh-cleanupendpad.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win32-seh-cleanupendpad.ll Thu Sep 10 17:00:02 2015
@@ -63,14 +63,22 @@ attributes #3 = { noinline }
 ; CHECK: retl
 
 ; CHECK: LBB0_[[inner:[0-9]+]]: # %ehcleanup
+; CHECK: pushl %ebp
+; CHECK: addl $12, %ebp
 ; CHECK: movl $0, -[[state]](%ebp)
 ; CHECK: movl $2, (%esp)
 ; CHECK: calll _f
+; CHECK: popl %ebp
+; CHECK: retl
 
 ; CHECK: LBB0_[[outer:[0-9]+]]: # %ehcleanup.3
+; CHECK: pushl %ebp
+; CHECK: addl $12, %ebp
 ; CHECK: movl $-1, -[[state]](%ebp)
 ; CHECK: movl $3, (%esp)
 ; CHECK: calll _f
+; CHECK: popl %ebp
+; CHECK: retl
 
 ; CHECK: L__ehtable$nested_finally:
 ; CHECK:        .long   -1