[AsmPrinterDwarf] Add support for .cfi_restore directive
As of today we only use .cfi_offset to specify the offset of a CSR, but
we never use .cfi_restore when the CSR is restored.
If we want to perform a more advanced type of shrink-wrapping, we need
to use .cfi_restore in order to switch the CFI state between blocks.
This patch only aims at adding support for the directive.
Differential Revision: https://reviews.llvm.org/D36114
llvm-svn: 317199
diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.cpp b/llvm/lib/CodeGen/MIRParser/MILexer.cpp
index 0ba346c..d23df9c 100644
--- a/llvm/lib/CodeGen/MIRParser/MILexer.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MILexer.cpp
@@ -216,6 +216,7 @@
.Case("def_cfa_register", MIToken::kw_cfi_def_cfa_register)
.Case("def_cfa_offset", MIToken::kw_cfi_def_cfa_offset)
.Case("def_cfa", MIToken::kw_cfi_def_cfa)
+ .Case("restore", MIToken::kw_cfi_restore)
.Case("blockaddress", MIToken::kw_blockaddress)
.Case("intrinsic", MIToken::kw_intrinsic)
.Case("target-index", MIToken::kw_target_index)
diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.h b/llvm/lib/CodeGen/MIRParser/MILexer.h
index 886916b..6894fe8 100644
--- a/llvm/lib/CodeGen/MIRParser/MILexer.h
+++ b/llvm/lib/CodeGen/MIRParser/MILexer.h
@@ -68,6 +68,7 @@
kw_cfi_def_cfa_register,
kw_cfi_def_cfa_offset,
kw_cfi_def_cfa,
+ kw_cfi_restore,
kw_blockaddress,
kw_intrinsic,
kw_target_index,
diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 1000eb0..9c8743a 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -1634,6 +1634,12 @@
CFIIndex =
MF.addFrameInst(MCCFIInstruction::createDefCfa(nullptr, Reg, -Offset));
break;
+ case MIToken::kw_cfi_restore:
+ if (parseCFIRegister(Reg))
+ return true;
+ CFIIndex = MF.addFrameInst(MCCFIInstruction::createRestore(nullptr, Reg));
+ break;
+
default:
// TODO: Parse the other CFI operands.
llvm_unreachable("The current token should be a cfi operand");
@@ -1912,6 +1918,7 @@
case MIToken::kw_cfi_def_cfa_register:
case MIToken::kw_cfi_def_cfa_offset:
case MIToken::kw_cfi_def_cfa:
+ case MIToken::kw_cfi_restore:
return parseCFIOperand(Dest);
case MIToken::kw_blockaddress:
return parseBlockAddressOperand(Dest);