Don't eliminate a partially redundant load if it's in a landing pad.

A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193064 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 0b8906d43f72c19d488019ea500d8ab2963e53d2..b3ec2fc84c03dac1d18cbb6dc3c4b87b7c3a43cb 100644 (file)
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -827,7 +827,6 @@ bool JumpThreading::ProcessBlock(BasicBlock *BB) {
   return false;
 }
 
-
 /// SimplifyPartiallyRedundantLoad - If LI is an obviously partially redundant
 /// load instruction, eliminate it by replacing it with a PHI node.  This is an
 /// important optimization that encourages jump threading, and needs to be run
@@ -842,6 +841,12 @@ bool JumpThreading::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
   if (LoadBB->getSinglePredecessor())
     return false;
 
+  // If the load is defined in a landing pad, it can't be partially redundant,
+  // because the edges between the invoke and the landing pad cannot have other
+  // instructions between them.
+  if (LoadBB->isLandingPad())
+    return false;
+
   Value *LoadedPtr = LI->getOperand(0);
 
   // If the loaded operand is defined in the LoadBB, it can't be available.

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 78217c8efa3dd894f9bf73a7b7cf44640d34c080..82b8da3a1070b2601682977281d3c91ffcab555e 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -503,19 +503,7 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
 
   // Splice all the instructions from PredBB to DestBB.
   PredBB->getTerminator()->eraseFromParent();
-
-  // First splice over the PHI nodes.
-  BasicBlock::iterator PI = PredBB->begin();
-  while (isa<PHINode>(PI))
-    ++PI;
-
-  if (PI != PredBB->begin())
-    DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList(),
-                                 PredBB->begin(), PI);
-
-  // Now splice over the rest of the instructions.
-  DestBB->getInstList().splice(DestBB->getFirstInsertionPt(),
-                               PredBB->getInstList(), PI, PredBB->end());
+  DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
 
   if (P) {
     DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>();
@@ -525,7 +513,6 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
       DT->eraseNode(PredBB);
     }
   }
-
   // Nuke BB.
   PredBB->eraseFromParent();
 }

diff --git a/test/Transforms/JumpThreading/landing-pad-splicing.ll b/test/Transforms/JumpThreading/landing-pad-splicing.ll
deleted file mode 100644 (file)
index 1ac0209..0000000
--- a/test/Transforms/JumpThreading/landing-pad-splicing.ll
+++ /dev/null
@@ -1,43 +0,0 @@
-; RUN: opt -S -jump-threading < %s -disable-output
-; PR17621
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
-target triple = "x86_64-apple-macosx10.8.0"
-
-declare void @_ZN1F7doApplyEv() unnamed_addr readnone align 2
-
-define void @_Z3fn1v() uwtable {
-entry:
-  store i32 0, i32* undef, align 4
-  invoke void @_ZN1F7doApplyEv()
-          to label %_ZN1D5applyEv.exit unwind label %lpad1
-
-_ZN1D5applyEv.exit:
-  invoke void @_ZN1F10insertTextEv()
-          to label %invoke.cont7 unwind label %lpad1
-
-invoke.cont7:
-  ret void
-
-lpad1:
-  %tmp1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
-          cleanup
-  %tmp2 = load i32* undef, align 4
-  %tobool.i.i.i = icmp eq i32 %tmp2, 0
-  br i1 %tobool.i.i.i, label %_ZN1BI1FED1Ev.exit, label %if.then.i.i.i
-
-if.then.i.i.i:
-  br i1 undef, label %_ZN1BI1FED1Ev.exit, label %delete.notnull.i.i.i
-
-delete.notnull.i.i.i:
-  unreachable
-
-_ZN1BI1FED1Ev.exit:
-  br label %eh.resume
-
-eh.resume:
-  resume { i8*, i32 } undef
-}
-
-declare i32 @__gxx_personality_v0(...)
-
-declare void @_ZN1F10insertTextEv()

diff --git a/test/Transforms/JumpThreading/landing-pad.ll b/test/Transforms/JumpThreading/landing-pad.ll
new file mode 100644 (file)
index 0000000..9ee0526
--- /dev/null
+++ b/test/Transforms/JumpThreading/landing-pad.ll
@@ -0,0 +1,203 @@
+; RUN: opt < %s -disable-output -jump-threading
+
+%class.E = type { i32 (...)**, %class.C }
+%class.C = type { %class.A }
+%class.A = type { i32 }
+%class.D = type { %class.F }
+%class.F = type { %class.E }
+%class.B = type { %class.D* }
+
+@_ZTV1D = unnamed_addr constant [3 x i8*] [i8* null, i8* bitcast ({ i8*, i8*, i8* }* @_ZTI1D to i8*), i8* bitcast (void (%class.D*)* @_ZN1D7doApplyEv to i8*)]
+@_ZTI1D = external unnamed_addr constant { i8*, i8*, i8* }
+
+define void @_ZN15EditCommandImpl5applyEv(%class.E* %this) uwtable align 2 {
+entry:
+  %0 = bitcast %class.E* %this to void (%class.E*)***
+  %vtable = load void (%class.E*)*** %0, align 8
+  %1 = load void (%class.E*)** %vtable, align 8
+  call void %1(%class.E* %this)
+  ret void
+}
+
+define void @_ZN1DC1Ev(%class.D* nocapture %this) unnamed_addr uwtable align 2 {
+entry:
+  call void @_ZN24CompositeEditCommandImplC2Ev()
+  %0 = getelementptr inbounds %class.D* %this, i64 0, i32 0, i32 0, i32 0
+  store i32 (...)** bitcast (i8** getelementptr inbounds ([3 x i8*]* @_ZTV1D, i64 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  ret void
+}
+
+define void @_ZN1DC2Ev(%class.D* nocapture %this) unnamed_addr uwtable align 2 {
+entry:
+  call void @_ZN24CompositeEditCommandImplC2Ev()
+  %0 = getelementptr inbounds %class.D* %this, i64 0, i32 0, i32 0, i32 0
+  store i32 (...)** bitcast (i8** getelementptr inbounds ([3 x i8*]* @_ZTV1D, i64 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  ret void
+}
+
+declare void @_ZN24CompositeEditCommandImplC2Ev() #1
+
+define void @_ZN1D7doApplyEv(%class.D* nocapture %this) unnamed_addr nounwind readnone uwtable align 2 {
+entry:
+  ret void
+}
+
+define void @_Z3fn1v() uwtable {
+entry:
+  %call = call noalias i8* @_Znwm() #8
+  invoke void @_ZN24CompositeEditCommandImplC2Ev()
+          to label %_ZN1DC1Ev.exit unwind label %lpad
+
+_ZN1DC1Ev.exit:                                   ; preds = %entry
+  %0 = bitcast i8* %call to i32 (...)***
+  store i32 (...)** bitcast (i8** getelementptr inbounds ([3 x i8*]* @_ZTV1D, i64 0, i64 2) to i32 (...)**), i32 (...)*** %0, align 8
+  %_ref.i.i.i = getelementptr inbounds i8* %call, i64 8
+  %1 = bitcast i8* %_ref.i.i.i to i32*
+  %2 = load i32* %1, align 4
+  %inc.i.i.i = add nsw i32 %2, 1
+  store i32 %inc.i.i.i, i32* %1, align 4
+  %3 = bitcast i8* %call to %class.D*
+  invoke void @_ZN1D7doApplyEv(%class.D* %3)
+          to label %_ZN15EditCommandImpl5applyEv.exit unwind label %lpad1
+
+_ZN15EditCommandImpl5applyEv.exit:                ; preds = %_ZN1DC1Ev.exit
+  invoke void @_ZN1D16deleteKeyPressedEv()
+          to label %invoke.cont7 unwind label %lpad1
+
+invoke.cont7:                                     ; preds = %_ZN15EditCommandImpl5applyEv.exit
+  ret void
+
+lpad:                                             ; preds = %entry
+  %4 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+          cleanup
+  call void @_ZdlPv() #9
+  unreachable
+
+lpad1:                                            ; preds = %_ZN1DC1Ev.exit, %_ZN15EditCommandImpl5applyEv.exit
+  %5 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+          cleanup
+  %6 = load i32* %1, align 4
+  %tobool.i.i.i = icmp eq i32 %6, 0
+  br i1 %tobool.i.i.i, label %_ZN1BI1DED1Ev.exit, label %if.then.i.i.i
+
+if.then.i.i.i:                                    ; preds = %lpad1
+  br i1 undef, label %_ZN1BI1DED1Ev.exit, label %delete.notnull.i.i.i
+
+delete.notnull.i.i.i:                             ; preds = %if.then.i.i.i
+  call void @_ZdlPv() #9
+  unreachable
+
+_ZN1BI1DED1Ev.exit:                               ; preds = %lpad1, %if.then.i.i.i
+  resume { i8*, i32 } undef
+
+terminate.lpad:                                   ; No predecessors!
+  %7 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+          catch i8* null
+  unreachable
+}
+
+define void @_ZN1BI1DEC1EPS0_(%class.B* nocapture %this, %class.D* %p1) unnamed_addr uwtable align 2 {
+entry:
+  %m_ptr.i = getelementptr inbounds %class.B* %this, i64 0, i32 0
+  store %class.D* %p1, %class.D** %m_ptr.i, align 8
+  %_ref.i.i = getelementptr inbounds %class.D* %p1, i64 0, i32 0, i32 0, i32 1, i32 0, i32 0
+  %0 = load i32* %_ref.i.i, align 4
+  %inc.i.i = add nsw i32 %0, 1
+  store i32 %inc.i.i, i32* %_ref.i.i, align 4
+  ret void
+}
+
+declare noalias i8* @_Znwm()
+
+declare i32 @__gxx_personality_v0(...)
+
+declare void @_ZdlPv()
+
+define %class.D* @_ZN1BI1DEptEv(%class.B* nocapture readonly %this) nounwind readonly uwtable align 2 {
+entry:
+  %m_ptr = getelementptr inbounds %class.B* %this, i64 0, i32 0
+  %0 = load %class.D** %m_ptr, align 8
+  ret %class.D* %0
+}
+
+declare void @_ZN1D16deleteKeyPressedEv()
+
+define void @_ZN1BI1DED1Ev(%class.B* nocapture readonly %this) unnamed_addr uwtable align 2 {
+entry:
+  %m_ptr.i = getelementptr inbounds %class.B* %this, i64 0, i32 0
+  %0 = load %class.D** %m_ptr.i, align 8
+  %_ref.i.i = getelementptr inbounds %class.D* %0, i64 0, i32 0, i32 0, i32 1, i32 0, i32 0
+  %1 = load i32* %_ref.i.i, align 4
+  %tobool.i.i = icmp eq i32 %1, 0
+  br i1 %tobool.i.i, label %_ZN1BI1DED2Ev.exit, label %if.then.i.i
+
+if.then.i.i:                                      ; preds = %entry
+  br i1 undef, label %_ZN1BI1DED2Ev.exit, label %delete.notnull.i.i
+
+delete.notnull.i.i:                               ; preds = %if.then.i.i
+  call void @_ZdlPv() #9
+  unreachable
+
+_ZN1BI1DED2Ev.exit:                               ; preds = %entry, %if.then.i.i
+  ret void
+}
+
+declare hidden void @__clang_call_terminate()
+
+define void @_ZN1BI1DED2Ev(%class.B* nocapture readonly %this) unnamed_addr uwtable align 2 {
+entry:
+  %m_ptr = getelementptr inbounds %class.B* %this, i64 0, i32 0
+  %0 = load %class.D** %m_ptr, align 8
+  %_ref.i = getelementptr inbounds %class.D* %0, i64 0, i32 0, i32 0, i32 1, i32 0, i32 0
+  %1 = load i32* %_ref.i, align 4
+  %tobool.i = icmp eq i32 %1, 0
+  br i1 %tobool.i, label %_ZN1AI1CE5derefEv.exit, label %if.then.i
+
+if.then.i:                                        ; preds = %entry
+  br i1 undef, label %_ZN1AI1CE5derefEv.exit, label %delete.notnull.i
+
+delete.notnull.i:                                 ; preds = %if.then.i
+  call void @_ZdlPv() #9
+  unreachable
+
+_ZN1AI1CE5derefEv.exit:                           ; preds = %entry, %if.then.i
+  ret void
+}
+
+define void @_ZN1AI1CE5derefEv(%class.A* nocapture readonly %this) nounwind uwtable align 2 {
+entry:
+  %_ref = getelementptr inbounds %class.A* %this, i64 0, i32 0
+  %0 = load i32* %_ref, align 4
+  %tobool = icmp eq i32 %0, 0
+  br i1 %tobool, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  br i1 undef, label %if.end, label %delete.notnull
+
+delete.notnull:                                   ; preds = %if.then
+  call void @_ZdlPv() #9
+  unreachable
+
+if.end:                                           ; preds = %entry, %if.then
+  ret void
+}
+
+define void @_ZN1BI1DEC2EPS0_(%class.B* nocapture %this, %class.D* %p1) unnamed_addr uwtable align 2 {
+entry:
+  %m_ptr = getelementptr inbounds %class.B* %this, i64 0, i32 0
+  store %class.D* %p1, %class.D** %m_ptr, align 8
+  %_ref.i = getelementptr inbounds %class.D* %p1, i64 0, i32 0, i32 0, i32 1, i32 0, i32 0
+  %0 = load i32* %_ref.i, align 4
+  %inc.i = add nsw i32 %0, 1
+  store i32 %inc.i, i32* %_ref.i, align 4
+  ret void
+}
+
+define void @_ZN1AI1CE3refEv(%class.A* nocapture %this) nounwind uwtable align 2 {
+entry:
+  %_ref = getelementptr inbounds %class.A* %this, i64 0, i32 0
+  %0 = load i32* %_ref, align 4
+  %inc = add nsw i32 %0, 1
+  store i32 %inc, i32* %_ref, align 4
+  ret void
+}