[llvm] 38292f0 - [Assignment Tracking] Fix assertion in AssignmentTrackingPass::runOnFunction
via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 12 04:36:45 PDT 2023
Author: OCHyams
Date: 2023-04-12T12:33:52+01:00
New Revision: 38292f0e1451ca4d4cde6759ab113d8eefed4d22
URL: https://github.com/llvm/llvm-project/commit/38292f0e1451ca4d4cde6759ab113d8eefed4d22
DIFF: https://github.com/llvm/llvm-project/commit/38292f0e1451ca4d4cde6759ab113d8eefed4d22.diff
LOG: [Assignment Tracking] Fix assertion in AssignmentTrackingPass::runOnFunction
The assertion exists to ensure all variables passed into `trackAssignments` end
up with dbg.assigns associated with their backing allocas. The assertion
compared the passed-in and tracked variables using `DebugVariable`, which
includes the fragment as part of the variable identity.
It is possible for the backing alloca to be smaller than a variable (see test
case). In this case the input variable `(Var X, no fragment, no InlinedAt)`
isn't equal to the dbg.assign variable `(Var X, some fragment, no
InlinedAt)`. To cover this case the assertion now ignores fragments through the
use of `DebugVariableAggregate`.
Reviewed By: jmorse
Differential Revision: https://reviews.llvm.org/D148100
Added:
llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/long-double-x87.ll
Modified:
llvm/lib/IR/DebugInfo.cpp
Removed:
################################################################################
diff --git a/llvm/lib/IR/DebugInfo.cpp b/llvm/lib/IR/DebugInfo.cpp
index 9073e59723233..0272ef2647a6a 100644
--- a/llvm/lib/IR/DebugInfo.cpp
+++ b/llvm/lib/IR/DebugInfo.cpp
@@ -2025,10 +2025,14 @@ bool AssignmentTrackingPass::runOnFunction(Function &F) {
(void)Markers;
for (DbgDeclareInst *DDI : P.second) {
// Assert that the alloca that DDI uses is now linked to a dbg.assign
- // describing the same variable (i.e. check that this dbg.declare
- // has been replaced by a dbg.assign).
+ // describing the same variable (i.e. check that this dbg.declare has
+ // been replaced by a dbg.assign). Use DebugVariableAggregate to Discard
+ // the fragment part because trackAssignments may alter the
+ // fragment. e.g. if the alloca is smaller than the variable, then
+ // trackAssignments will create an alloca-sized fragment for the
+ // dbg.assign.
assert(llvm::any_of(Markers, [DDI](DbgAssignIntrinsic *DAI) {
- return DebugVariable(DAI) == DebugVariable(DDI);
+ return DebugVariableAggregate(DAI) == DebugVariableAggregate(DDI);
}));
// Delete DDI because the variable location is now tracked using
// assignment tracking.
diff --git a/llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/long-double-x87.ll b/llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/long-double-x87.ll
new file mode 100644
index 0000000000000..5e308097fd1ae
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/long-double-x87.ll
@@ -0,0 +1,39 @@
+; RUN: opt %s -S -passes=declare-to-assign -o - | FileCheck %s
+
+;; Generated from this C++:
+;; long double get();
+;; void fun() {
+;; long double f;
+;; }
+
+;; Check a variable that is larger (128 bits according to !15) than its backing
+;; alloca (80 bits) can be represented with assignment tracking. Create a
+;; fragment for the dbg.assign for bits 0-80.
+
+; CHECK: llvm.dbg.assign(metadata i1 undef, metadata ![[#]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 80), metadata ![[#]], metadata ptr %f, metadata !DIExpression())
+
+define dso_local void @_Z3funv() #0 !dbg !10 {
+entry:
+ %f = alloca x86_fp80, align 16
+ call void @llvm.dbg.declare(metadata ptr %f, metadata !14, metadata !DIExpression()), !dbg !16
+ ret void
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 17.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{!"clang version 17.0.0"}
+!10 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 2, type: !11, scopeLine: 2, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !13)
+!11 = !DISubroutineType(types: !12)
+!12 = !{null}
+!13 = !{}
+!14 = !DILocalVariable(name: "f", scope: !10, file: !1, line: 3, type: !15)
+!15 = !DIBasicType(name: "long double", size: 128, encoding: DW_ATE_float)
+!16 = !DILocation(line: 3, column: 15, scope: !10)
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