GlobalISel: put debug info for static allocas in the MachineFunction.
The good reason to do this is that static allocas are pretty simple to handle
(especially at -O0) and avoiding tracking DBG_VALUEs throughout the pipeline
should give some kind of performance benefit.
The bad reason is that the debug pipeline is an unholy mess of implicit
contracts, where determining whether "DBG_VALUE %reg, imm" actually implies a
load or not involves the services of at least 3 soothsayers and the sacrifice
of at least one chicken. And it still gets it wrong if the variable is at SP
directly.
llvm-svn: 297410
GitOrigin-RevId: 7a9ea8f628f863c2cde41e63be45a2e47fbd95ef
diff --git a/lib/CodeGen/GlobalISel/IRTranslator.cpp b/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 4d1ac68..b6ce59d 100644
--- a/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -598,18 +598,18 @@
return true;
}
- unsigned Reg = getOrCreateVReg(*Address);
- auto RegDef = MRI->def_instr_begin(Reg);
assert(DI.getVariable()->isValidLocationForIntrinsic(
MIRBuilder.getDebugLoc()) &&
"Expected inlined-at fields to agree");
-
- if (RegDef != MRI->def_instr_end() &&
- RegDef->getOpcode() == TargetOpcode::G_FRAME_INDEX) {
- MIRBuilder.buildFIDbgValue(RegDef->getOperand(1).getIndex(),
- DI.getVariable(), DI.getExpression());
+ auto AI = dyn_cast<AllocaInst>(Address);
+ if (AI && AI->isStaticAlloca()) {
+ // Static allocas are tracked at the MF level, no need for DBG_VALUE
+ // instructions (in fact, they get ignored if they *do* exist).
+ MF->setVariableDbgInfo(DI.getVariable(), DI.getExpression(),
+ getOrCreateFrameIndex(*AI), DI.getDebugLoc());
} else
- MIRBuilder.buildDirectDbgValue(Reg, DI.getVariable(), DI.getExpression());
+ MIRBuilder.buildDirectDbgValue(getOrCreateVReg(*Address),
+ DI.getVariable(), DI.getExpression());
return true;
}
case Intrinsic::vaend:
diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp
index 831e7d8..ef5e032 100644
--- a/lib/CodeGen/MachineFunction.cpp
+++ b/lib/CodeGen/MachineFunction.cpp
@@ -169,6 +169,7 @@
InstructionRecycler.clear(Allocator);
OperandRecycler.clear(Allocator);
BasicBlockRecycler.clear(Allocator);
+ VariableDbgInfos.clear();
if (RegInfo) {
RegInfo->~MachineRegisterInfo();
Allocator.Deallocate(RegInfo);
diff --git a/test/CodeGen/AArch64/GlobalISel/debug-insts.ll b/test/CodeGen/AArch64/GlobalISel/debug-insts.ll
index 2c3def2..5a76661 100644
--- a/test/CodeGen/AArch64/GlobalISel/debug-insts.ll
+++ b/test/CodeGen/AArch64/GlobalISel/debug-insts.ll
@@ -1,8 +1,10 @@
; RUN: llc -global-isel -mtriple=aarch64 %s -stop-after=irtranslator -o - | FileCheck %s
-
+; RUN: llc -mtriple=aarch64 -global-isel --global-isel-abort=0 -o /dev/null
; CHECK-LABEL: name: debug_declare
-; CHECK: DBG_VALUE %stack.0.in.addr, 0, !11, !12, debug-location !13
+; CHECK: stack:
+; CHECK: - { id: {{.*}}, name: in.addr, offset: {{.*}}, size: {{.*}}, alignment: {{.*}}, di-variable: '!11',
+; CHECK-NEXT: di-expression: '!12', di-location: '!13' }
; CHECK: DBG_VALUE debug-use %0(s32), debug-use _, !11, !12, debug-location !13
define void @debug_declare(i32 %in) #0 !dbg !7 {
entry:
@@ -13,6 +15,15 @@
ret void, !dbg !14
}
+; CHECK-LABEL: name: debug_declare_vla
+; CHECK: DBG_VALUE debug-use %{{[0-9]+}}(p0), debug-use _, !11, !12, debug-location !13
+define void @debug_declare_vla(i32 %in) #0 !dbg !7 {
+entry:
+ %vla.addr = alloca i32, i32 %in
+ call void @llvm.dbg.declare(metadata i32* %vla.addr, metadata !11, metadata !12), !dbg !13
+ ret void, !dbg !14
+}
+
; CHECK-LABEL: name: debug_value
; CHECK: [[IN:%[0-9]+]](s32) = COPY %w0
define void @debug_value(i32 %in) #0 !dbg !7 {
