[llvm] e0374fb - [DebugInfo] Make debug intrinsics to track cloned values in JumpThreading
Stephen Tozer via llvm-commits
llvm-commits at lists.llvm.org
Wed Feb 1 04:54:26 PST 2023
Author: Ben Mudd
Date: 2023-02-01T12:52:37Z
New Revision: e0374fb2f447c5302fec21a2999c5ea082661db6
URL: https://github.com/llvm/llvm-project/commit/e0374fb2f447c5302fec21a2999c5ea082661db6
DIFF: https://github.com/llvm/llvm-project/commit/e0374fb2f447c5302fec21a2999c5ea082661db6.diff
LOG: [DebugInfo] Make debug intrinsics to track cloned values in JumpThreading
This patch causes debug value intrinsics outside of cloned blocks in the
Jump Threading pass to correctly point towards any derived values. If it cannot,
it kills them.
Reviewed By: probinson, StephenTozer
Differential Revision: https://reviews.llvm.org/D140404
Added:
Modified:
llvm/include/llvm/Transforms/Utils/SSAUpdater.h
llvm/lib/Transforms/Scalar/JumpThreading.cpp
llvm/lib/Transforms/Utils/SSAUpdater.cpp
llvm/test/Transforms/JumpThreading/thread-debug-info.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
index c233e3dc168ed..36fbf536f6d01 100644
--- a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
+++ b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
@@ -28,6 +28,7 @@ template <typename T> class SSAUpdaterTraits;
class Type;
class Use;
class Value;
+class DbgValueInst;
/// Helper class for SSA formation on a set of values defined in
/// multiple blocks.
@@ -114,6 +115,15 @@ class SSAUpdater {
/// be below it.
void RewriteUse(Use &U);
+ /// Rewrite debug value intrinsics to conform to a new SSA form.
+ ///
+ /// This will scout out all the debug value instrinsics associated with
+ /// the instruction. Anything outside of its block will have its
+ /// value set to the new SSA value if available, and undef if not.
+ void UpdateDebugValues(Instruction *I);
+ void UpdateDebugValues(Instruction *I,
+ SmallVectorImpl<DbgValueInst *> &DbgValues);
+
/// Rewrite a use like \c RewriteUse but handling in-block definitions.
///
/// This version of the method can rewrite uses in the same block as
@@ -123,6 +133,7 @@ class SSAUpdater {
private:
Value *GetValueAtEndOfBlockInternal(BasicBlock *BB);
+ void UpdateDebugValue(Instruction *I, DbgValueInst *DbgValue);
};
/// Helper class for promoting a collection of loads and stores into SSA
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index f41eaed2e3e7e..bd5d9ef7f097e 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -40,6 +40,7 @@
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstrTypes.h"
@@ -2038,6 +2039,7 @@ void JumpThreadingPass::updateSSA(
// PHI insertion, of which we are prepared to do, clean these up now.
SSAUpdater SSAUpdate;
SmallVector<Use *, 16> UsesToRename;
+ SmallVector<DbgValueInst *, 4> DbgValues;
for (Instruction &I : *BB) {
// Scan all uses of this instruction to see if it is used outside of its
@@ -2053,8 +2055,16 @@ void JumpThreadingPass::updateSSA(
UsesToRename.push_back(&U);
}
+ // Find debug values outside of the block
+ findDbgValues(DbgValues, &I);
+ DbgValues.erase(remove_if(DbgValues,
+ [&](const DbgValueInst *DbgVal) {
+ return DbgVal->getParent() == BB;
+ }),
+ DbgValues.end());
+
// If there are no uses outside the block, we're done with this instruction.
- if (UsesToRename.empty())
+ if (UsesToRename.empty() && DbgValues.empty())
continue;
LLVM_DEBUG(dbgs() << "JT: Renaming non-local uses of: " << I << "\n");
@@ -2067,6 +2077,11 @@ void JumpThreadingPass::updateSSA(
while (!UsesToRename.empty())
SSAUpdate.RewriteUse(*UsesToRename.pop_back_val());
+ if (!DbgValues.empty()) {
+ SSAUpdate.UpdateDebugValues(&I, DbgValues);
+ DbgValues.clear();
+ }
+
LLVM_DEBUG(dbgs() << "\n");
}
}
diff --git a/llvm/lib/Transforms/Utils/SSAUpdater.cpp b/llvm/lib/Transforms/Utils/SSAUpdater.cpp
index 2520aa5d9db00..13975ded64161 100644
--- a/llvm/lib/Transforms/Utils/SSAUpdater.cpp
+++ b/llvm/lib/Transforms/Utils/SSAUpdater.cpp
@@ -19,6 +19,7 @@
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
@@ -195,6 +196,33 @@ void SSAUpdater::RewriteUse(Use &U) {
U.set(V);
}
+void SSAUpdater::UpdateDebugValues(Instruction *I) {
+ SmallVector<DbgValueInst *, 4> DbgValues;
+ llvm::findDbgValues(DbgValues, I);
+ for (auto &DbgValue : DbgValues) {
+ if (DbgValue->getParent() == I->getParent())
+ continue;
+ UpdateDebugValue(I, DbgValue);
+ }
+}
+
+void SSAUpdater::UpdateDebugValues(Instruction *I,
+ SmallVectorImpl<DbgValueInst *> &DbgValues) {
+ for (auto &DbgValue : DbgValues) {
+ UpdateDebugValue(I, DbgValue);
+ }
+}
+
+void SSAUpdater::UpdateDebugValue(Instruction *I, DbgValueInst *DbgValue) {
+ BasicBlock *UserBB = DbgValue->getParent();
+ if (HasValueForBlock(UserBB)) {
+ Value *NewVal = GetValueInMiddleOfBlock(UserBB);
+ DbgValue->replaceVariableLocationOp(I, NewVal);
+ }
+ else
+ DbgValue->setKillLocation();
+}
+
void SSAUpdater::RewriteUseAfterInsertions(Use &U) {
Instruction *User = cast<Instruction>(U.getUser());
diff --git a/llvm/test/Transforms/JumpThreading/thread-debug-info.ll b/llvm/test/Transforms/JumpThreading/thread-debug-info.ll
index b85a8fb719500..03478292779c3 100644
--- a/llvm/test/Transforms/JumpThreading/thread-debug-info.ll
+++ b/llvm/test/Transforms/JumpThreading/thread-debug-info.ll
@@ -3,7 +3,7 @@
@a = global i32 0, align 4
; Test that the llvm.dbg.value calls in a threaded block are correctly updated to
; target the locals in their threaded block, and not the unthreaded one.
-define void @test2(i32 %cond1, i32 %cond2) {
+define void @test1(i32 %cond1, i32 %cond2) {
; CHECK: [[globalptr:@.*]] = global i32 0, align 4
; CHECK: bb.cond2:
; CHECK: call void @llvm.dbg.value(metadata ptr null, metadata ![[DBG1ptr:[0-9]+]], metadata !DIExpression()), !dbg ![[DBG2ptr:[0-9]+]]
@@ -49,6 +49,48 @@ exit: ; preds = %bb.f4, %bb.f3, %bb.
ret void, !dbg !29
}
+; This is testing for debug value instrinsics outside of the threaded block pointing to a value
+; inside to correctly take any new definitions.
+define void @test2(i32 %cond1, i32 %cond2) !dbg !5 {
+; CHECK: bb.f3
+; CHECK: call void @llvm.dbg.value(metadata ptr @a, metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+; CHECK: bb.f4
+; CHECK-NEXT: [[PTR3:%.*]] = phi ptr [ null, %bb.cond2 ]
+; CHECK-NEXT: call void @llvm.dbg.value(metadata ptr [[PTR3]], metadata !{{[0-9]+}}, metadata !DIExpression()), !dbg !{{[0-9]+}}
+entry:
+ %tobool = icmp eq i32 %cond1, 0, !dbg !15
+ br i1 %tobool, label %bb.cond2, label %bb.f1, !dbg !16
+
+bb.f1: ; preds = %entry
+ call void @f1(), !dbg !17
+ br label %bb.cond2, !dbg !18
+
+bb.cond2: ; preds = %bb.f1, %entry
+ %ptr = phi ptr [ null, %bb.f1 ], [ @a, %entry ], !dbg !19
+ %tobool1 = icmp eq i32 %cond2, 0, !dbg !20
+ br i1 %tobool1, label %bb.file, label %bb.f2, !dbg !21
+
+bb.f2: ; preds = %bb.cond2
+ call void @f2(), !dbg !22
+ br label %exit, !dbg !23
+
+bb.file: ; preds = %bb.cond2
+ %cmp = icmp eq ptr %ptr, null, !dbg !24
+ call void @llvm.dbg.value(metadata ptr %ptr, metadata !14, metadata !DIExpression()), !dbg !21
+ br i1 %cmp, label %bb.f4, label %bb.f3, !dbg !25
+
+bb.f3: ; preds = %bb.file
+ call void @f3(), !dbg !26
+ br label %exit, !dbg !27
+
+bb.f4: ; preds = %bb.file
+ call void @f4(), !dbg !28
+ br label %exit, !dbg !29
+
+exit: ; preds = %bb.f4, %bb.f3, %bb.f2
+ ret void, !dbg !29
+}
+
declare void @f1()
declare void @f2()
@@ -95,4 +137,4 @@ attributes #0 = { nocallback nofree nosync nounwind speculatable willreturn memo
!26 = !DILocation(line: 12, column: 1, scope: !5)
!27 = !DILocation(line: 13, column: 1, scope: !5)
!28 = !DILocation(line: 14, column: 1, scope: !5)
-!29 = !DILocation(line: 15, column: 1, scope: !5)
\ No newline at end of file
+!29 = !DILocation(line: 15, column: 1, scope: !5)
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