[llvm] r358791 - [GVN+LICM] Use line 0 locations for better crash attribution
Vedant Kumar via llvm-commits
llvm-commits at lists.llvm.org
Fri Apr 19 15:36:40 PDT 2019
Author: vedantk
Date: Fri Apr 19 15:36:40 2019
New Revision: 358791
URL: http://llvm.org/viewvc/llvm-project?rev=358791&view=rev
Log:
[GVN+LICM] Use line 0 locations for better crash attribution
This is a follow-up to r291037+r291258, which used null debug locations
to prevent jumpy line tables.
Using line 0 locations achieves the same effect, but works better for
crash attribution because it preserves the right inline scope.
Differential Revision: https://reviews.llvm.org/D60913
Modified:
llvm/trunk/lib/Transforms/Scalar/GVN.cpp
llvm/trunk/lib/Transforms/Scalar/LICM.cpp
llvm/trunk/test/DebugInfo/Generic/licm-hoist-debug-loc.ll
llvm/trunk/test/Transforms/GVN/PRE/phi-translate.ll
Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=358791&r1=358790&r2=358791&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Fri Apr 19 15:36:40 2019
@@ -46,6 +46,7 @@
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
@@ -1206,9 +1207,8 @@ bool GVN::PerformLoadPRE(LoadInst *LI, A
// Instructions that have been inserted in predecessor(s) to materialize
// the load address do not retain their original debug locations. Doing
// so could lead to confusing (but correct) source attributions.
- // FIXME: How do we retain source locations without causing poor debugging
- // behavior?
- I->setDebugLoc(DebugLoc());
+ if (const DebugLoc &DL = I->getDebugLoc())
+ I->setDebugLoc(DebugLoc::get(0, 0, DL.getScope(), DL.getInlinedAt()));
// FIXME: We really _ought_ to insert these value numbers into their
// parent's availability map. However, in doing so, we risk getting into
Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=358791&r1=358790&r2=358791&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Fri Apr 19 15:36:40 2019
@@ -54,6 +54,7 @@
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
@@ -1652,13 +1653,10 @@ static void hoist(Instruction &I, const
// Move the new node to the destination block, before its terminator.
moveInstructionBefore(I, *Dest->getTerminator(), *SafetyInfo, MSSAU);
- // Do not retain debug locations when we are moving instructions to different
- // basic blocks, because we want to avoid jumpy line tables. Calls, however,
- // need to retain their debug locs because they may be inlined.
- // FIXME: How do we retain source locations without causing poor debugging
- // behavior?
- if (!isa<CallInst>(I))
- I.setDebugLoc(DebugLoc());
+ // Apply line 0 debug locations when we are moving instructions to different
+ // basic blocks because we want to avoid jumpy line tables.
+ if (const DebugLoc &DL = I.getDebugLoc())
+ I.setDebugLoc(DebugLoc::get(0, 0, DL.getScope(), DL.getInlinedAt()));
if (isa<LoadInst>(I))
++NumMovedLoads;
Modified: llvm/trunk/test/DebugInfo/Generic/licm-hoist-debug-loc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Generic/licm-hoist-debug-loc.ll?rev=358791&r1=358790&r2=358791&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/Generic/licm-hoist-debug-loc.ll (original)
+++ llvm/trunk/test/DebugInfo/Generic/licm-hoist-debug-loc.ll Fri Apr 19 15:36:40 2019
@@ -18,8 +18,9 @@
; We make sure that the instruction that is hoisted into the preheader
; does not have a debug location.
; CHECK: for.body.lr.ph:
-; CHECK: getelementptr{{.*}}%p.addr, i64 4{{$}}
+; CHECK: getelementptr{{.*}}%p.addr, i64 4{{.*}} !dbg [[zero:![0-9]+]]
; CHECK: for.body:
+; CHECK: [[zero]] = !DILocation(line: 0
;
; ModuleID = 't.ll'
source_filename = "test.c"
Modified: llvm/trunk/test/Transforms/GVN/PRE/phi-translate.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/PRE/phi-translate.ll?rev=358791&r1=358790&r2=358791&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/GVN/PRE/phi-translate.ll (original)
+++ llvm/trunk/test/Transforms/GVN/PRE/phi-translate.ll Fri Apr 19 15:36:40 2019
@@ -4,8 +4,8 @@ target datalayout = "e-p:64:64:64"
; CHECK-LABEL: @foo(
; CHECK: entry.end_crit_edge:
-; CHECK: %[[INDEX:[a-z0-9.]+]] = sext i32 %x to i64{{$}}
-; CHECK: %[[ADDRESS:[a-z0-9.]+]] = getelementptr [100 x i32], [100 x i32]* @G, i64 0, i64 %[[INDEX]]{{$}}
+; CHECK: %[[INDEX:[a-z0-9.]+]] = sext i32 %x to i64{{.*}} !dbg [[ZERO_LOC:![0-9]+]]
+; CHECK: %[[ADDRESS:[a-z0-9.]+]] = getelementptr [100 x i32], [100 x i32]* @G, i64 0, i64 %[[INDEX]]{{.*}} !dbg [[ZERO_LOC]]
; CHECK: %n.pre = load i32, i32* %[[ADDRESS]], !dbg [[N_LOC:![0-9]+]]
; CHECK: br label %end
; CHECK: then:
@@ -14,7 +14,8 @@ target datalayout = "e-p:64:64:64"
; CHECK: %n = phi i32 [ %n.pre, %entry.end_crit_edge ], [ %z, %then ], !dbg [[N_LOC]]
; CHECK: ret i32 %n
-; CHECK: [[N_LOC]] = !DILocation(line: 47, column: 1, scope: !{{.*}})
+; CHECK-DAG: [[N_LOC]] = !DILocation(line: 47, column: 1, scope: !{{.*}})
+; CHECK-DAG: [[ZERO_LOC]] = !DILocation(line: 0
@G = external global [100 x i32]
define i32 @foo(i32 %x, i32 %z) !dbg !6 {
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