[DebugInfo] Introduce DW_OP_LLVM_convert
Introduce a DW_OP_LLVM_convert Dwarf expression pseudo op that allows
for a convenient way to perform type conversions on the Dwarf expression
stack. As an additional bonus it paves the way for using other Dwarf
v5 ops that need to reference a base_type.
The new DW_OP_LLVM_convert is used from lib/Transforms/Utils/Local.cpp
to perform sext/zext on debug values but mainly the patch is about
preparing terrain for adding other Dwarf v5 ops that need to reference a
base_type.
For Dwarf v5 the op maps to DW_OP_convert and for earlier versions a
complex shift & mask pattern is generated to emulate sext/zext.
This is a recommit of r356442 with trivial fixes for the failing tests.
Differential Revision: https://reviews.llvm.org/D56587
llvm-svn: 356451
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index af3db51..07dea40 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -2123,8 +2123,13 @@
assert(!OpStr.empty() && "Expected valid opcode");
Out << FS << OpStr;
- for (unsigned A = 0, AE = I->getNumArgs(); A != AE; ++A)
- Out << FS << I->getArg(A);
+ if (I->getOp() == dwarf::DW_OP_LLVM_convert) {
+ Out << FS << I->getArg(0);
+ Out << FS << dwarf::AttributeEncodingString(I->getArg(1));
+ } else {
+ for (unsigned A = 0, AE = I->getNumArgs(); A != AE; ++A)
+ Out << FS << I->getArg(A);
+ }
}
} else {
for (const auto &I : N->getElements())