[llvm] 773f8db - [MC] Fix double negation of DW_CFA_def_cfa

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2020-05-22T21:02:53-07:00
New Revision: 773f8dbd1da8409f1b62e8c5692cb9a5d199d6c8

URL: https://github.com/llvm/llvm-project/commit/773f8dbd1da8409f1b62e8c5692cb9a5d199d6c8
DIFF: https://github.com/llvm/llvm-project/commit/773f8dbd1da8409f1b62e8c5692cb9a5d199d6c8.diff

LOG: [MC] Fix double negation of DW_CFA_def_cfa

Negations are incorrectly added in numerous places and the code just happens to work.
Also fix a missed DW_CFA_def_cfa_offset negation in c693b9c321d5a40d012340619674cf790c9ac86c:
ARMAsmBackendDarwin::generateCompactUnwindEncoding

Added: 
    

Modified: 
    llvm/lib/MC/MCDwarf.cpp
    llvm/lib/MC/MCStreamer.cpp
    llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
    llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp
    llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp
    llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index d0fb77f62918..0b7fc4554018 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/lib/MC/MCDwarf.cpp
@@ -1406,7 +1406,7 @@ void FrameEmitterImpl::emitCFIInstruction(const MCCFIInstruction &Instr) {
       Reg = MRI->getDwarfRegNumFromDwarfEHRegNum(Reg);
     Streamer.emitInt8(dwarf::DW_CFA_def_cfa);
     Streamer.emitULEB128IntValue(Reg);
-    CFAOffset = -Instr.getOffset();
+    CFAOffset = Instr.getOffset();
     Streamer.emitULEB128IntValue(CFAOffset);
 
     return;

diff  --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 5e24177274a6..be5d588140ba 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -461,7 +461,7 @@ MCSymbol *MCStreamer::emitCFILabel() {
 void MCStreamer::emitCFIDefCfa(int64_t Register, int64_t Offset) {
   MCSymbol *Label = emitCFILabel();
   MCCFIInstruction Instruction =
-      MCCFIInstruction::cfiDefCfa(Label, Register, -Offset);
+      MCCFIInstruction::cfiDefCfa(Label, Register, Offset);
   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
   if (!CurFrame)
     return;

diff  --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index 837d56598ac8..9ad595c016c4 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -1118,11 +1118,11 @@ uint32_t ARMAsmBackendDarwin::generateCompactUnwindEncoding(
     const MCCFIInstruction &Inst = Instrs[i];
     switch (Inst.getOperation()) {
     case MCCFIInstruction::OpDefCfa: // DW_CFA_def_cfa
-      CFARegisterOffset = -Inst.getOffset();
+      CFARegisterOffset = Inst.getOffset();
       CFARegister = *MRI.getLLVMRegNum(Inst.getRegister(), true);
       break;
     case MCCFIInstruction::OpDefCfaOffset: // DW_CFA_def_cfa_offset
-      CFARegisterOffset = -Inst.getOffset();
+      CFARegisterOffset = Inst.getOffset();
       break;
     case MCCFIInstruction::OpDefCfaRegister: // DW_CFA_def_cfa_register
       CFARegister = *MRI.getLLVMRegNum(Inst.getRegister(), true);

diff  --git a/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp b/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp
index 173059f3ed60..fb2bcdc6c91b 100644
--- a/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp
+++ b/llvm/lib/Target/Sparc/MCTargetDesc/SparcMCTargetDesc.cpp
@@ -47,7 +47,7 @@ static MCAsmInfo *createSparcV9MCAsmInfo(const MCRegisterInfo &MRI,
                                          const MCTargetOptions &Options) {
   MCAsmInfo *MAI = new SparcELFMCAsmInfo(TT);
   unsigned Reg = MRI.getDwarfRegNum(SP::O6, true);
-  MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, Reg, -2047);
+  MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, Reg, 2047);
   MAI->addInitialFrameState(Inst);
   return MAI;
 }

diff  --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp
index 4e4560c479f6..f2ef1ad6c698 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCTargetDesc.cpp
@@ -152,7 +152,7 @@ static MCAsmInfo *createSystemZMCAsmInfo(const MCRegisterInfo &MRI,
   MCAsmInfo *MAI = new SystemZMCAsmInfo(TT);
   MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(
       nullptr, MRI.getDwarfRegNum(SystemZ::R15D, true),
-      -SystemZMC::CFAOffsetFromInitialSP);
+      SystemZMC::CFAOffsetFromInitialSP);
   MAI->addInitialFrameState(Inst);
   return MAI;
 }

diff  --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp
index 2ba4c6db055a..81110ba666e9 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp
@@ -350,7 +350,7 @@ static MCAsmInfo *createX86MCAsmInfo(const MCRegisterInfo &MRI,
   // Initial state of the frame pointer is esp+stackGrowth.
   unsigned StackPtr = is64Bit ? X86::RSP : X86::ESP;
   MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(
-      nullptr, MRI.getDwarfRegNum(StackPtr, true), stackGrowth);
+      nullptr, MRI.getDwarfRegNum(StackPtr, true), -stackGrowth);
   MAI->addInitialFrameState(Inst);
 
   // Add return address to move list