[llvm-branch-commits] [llvm-branch] r73466 - /llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp

[Bill Wendling]

Author: void
Date: Mon Jun 15 23:07:13 2009
New Revision: 73466

URL: http://llvm.org/viewvc/llvm-project?rev=73466&view=rev
Log:
Merge in r73465:

The DWARF to compact encoding converter assumes that the DW_CFA_def_cfa_offset
comes after the DW_CFA_def_cfa_register, because the CFA is really ESP from the
start of the function and only gets an offset when the "subl $xxx,%esp"
instruction happens, not the other way around.

And reapply r72898:

The DWARF unwind info was incorrect. While compiling with
`-fomit-frame-pointer', we would lack the DW_CFA_advance_loc information for a
lot of function, and then they would be `0'. The linker (at least on Darwin)
needs to encode the stack size. In some cases, the stack size is too large to
directly encode. So the linker checks to see if there is a "subl $xxx,%esp"
instruction at the point where the `DW_CFA_def_cfa_offset' says the pc was. If
so, the compact encoding records the offset in the function to where the stack
size is embedded. But because the `DW_CFA_advance_loc' instructions are missing,
it looks before the function and dies.

So, instead of emitting the EH debug label before the stack adjustment
operations, emit it afterwards, right before the frame move stuff.

Modified:
    llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp

Modified: llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp?rev=73466&r1=73465&r2=73466&view=diff

==============================================================================
--- llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp (original)
+++ llvm/branches/Apple/Bender/lib/Target/X86/X86RegisterInfo.cpp Mon Jun 15 23:07:13 2009
@@ -662,6 +662,17 @@
      TargetFrameInfo::StackGrowsUp ?
      TD->getPointerSize() : -TD->getPointerSize());
 
+  if (hasFP(MF)) {
+    // Save FP
+    MachineLocation FPDst(MachineLocation::VirtualFP, 2*stackGrowth);
+    MachineLocation FPSrc(FramePtr);
+    Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
+  }
+
+  MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
+  MachineLocation FPSrc(MachineLocation::VirtualFP);
+  Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
+
   if (StackSize) {
     // Show update of SP.
     if (hasFP(MF)) {
@@ -676,7 +687,7 @@
       Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
     }
   } else {
-    //FIXME: Verify & implement for FP
+    // FIXME: Verify & implement for FP
     MachineLocation SPDst(StackPtr);
     MachineLocation SPSrc(StackPtr, stackGrowth);
     Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
@@ -704,17 +715,6 @@
     MachineLocation CSSrc(Reg);
     Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
   }
-
-  if (hasFP(MF)) {
-    // Save FP
-    MachineLocation FPDst(MachineLocation::VirtualFP, 2*stackGrowth);
-    MachineLocation FPSrc(FramePtr);
-    Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
-  }
-
-  MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
-  MachineLocation FPSrc(MachineLocation::VirtualFP);
-  Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
 }
 
 
@@ -820,13 +820,6 @@
     NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
   }
 
-  unsigned ReadyLabelId = 0;
-  if (needsFrameMoves) {
-    // Mark effective beginning of when frame pointer is ready.
-    ReadyLabelId = MMI->NextLabelID();
-    BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(ReadyLabelId);
-  }
-
   // Skip the callee-saved push instructions.
   while (MBBI != MBB.end() &&
          (MBBI->getOpcode() == X86::PUSH32r ||
@@ -887,8 +880,13 @@
     }
   }
 
-  if (needsFrameMoves)
+  if (needsFrameMoves) {
+    unsigned ReadyLabelId = 0;
+    // Mark effective beginning of when frame pointer is ready.
+    ReadyLabelId = MMI->NextLabelID();
+    BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(ReadyLabelId);
     emitFrameMoves(MF, FrameLabelId, ReadyLabelId);
+  }
 }
 
 void X86RegisterInfo::emitEpilogue(MachineFunction &MF,