[llvm] r278938 - Revert "Reassociate: Reprocess RedoInsts after each inst".
Chad Rosier via llvm-commits
llvm-commits at lists.llvm.org
Wed Aug 17 08:54:40 PDT 2016
Author: mcrosier
Date: Wed Aug 17 10:54:39 2016
New Revision: 278938
URL: http://llvm.org/viewvc/llvm-project?rev=278938&view=rev
Log:
Revert "Reassociate: Reprocess RedoInsts after each inst".
This reverts commit r258830, which introduced a bug described in PR28367.
PR28367
Removed:
llvm/trunk/test/Transforms/Reassociate/prev_insts_canonicalized.ll
Modified:
llvm/trunk/include/llvm/Transforms/Scalar/Reassociate.h
llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
llvm/trunk/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll
llvm/trunk/test/Transforms/Reassociate/xor_reassoc.ll
Modified: llvm/trunk/include/llvm/Transforms/Scalar/Reassociate.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar/Reassociate.h?rev=278938&r1=278937&r2=278938&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Scalar/Reassociate.h (original)
+++ llvm/trunk/include/llvm/Transforms/Scalar/Reassociate.h Wed Aug 17 10:54:39 2016
@@ -65,7 +65,7 @@ public:
PreservedAnalyses run(Function &F, FunctionAnalysisManager &);
private:
- void BuildRankMap(Function &F, ReversePostOrderTraversal<Function *> &RPOT);
+ void BuildRankMap(Function &F);
unsigned getRank(Value *V);
void canonicalizeOperands(Instruction *I);
void ReassociateExpression(BinaryOperator *I);
Modified: llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp?rev=278938&r1=278937&r2=278938&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp Wed Aug 17 10:54:39 2016
@@ -145,8 +145,7 @@ static BinaryOperator *isReassociableOp(
return nullptr;
}
-void ReassociatePass::BuildRankMap(
- Function &F, ReversePostOrderTraversal<Function *> &RPOT) {
+void ReassociatePass::BuildRankMap(Function &F) {
unsigned i = 2;
// Assign distinct ranks to function arguments.
@@ -155,6 +154,7 @@ void ReassociatePass::BuildRankMap(
DEBUG(dbgs() << "Calculated Rank[" << I->getName() << "] = " << i << "\n");
}
+ ReversePostOrderTraversal<Function *> RPOT(&F);
for (BasicBlock *BB : RPOT) {
unsigned BBRank = RankMap[BB] = ++i << 16;
@@ -2172,28 +2172,13 @@ void ReassociatePass::ReassociateExpress
}
PreservedAnalyses ReassociatePass::run(Function &F, FunctionAnalysisManager &) {
- // Reassociate needs for each instruction to have its operands already
- // processed, so we first perform a RPOT of the basic blocks so that
- // when we process a basic block, all its dominators have been processed
- // before.
- ReversePostOrderTraversal<Function *> RPOT(&F);
- BuildRankMap(F, RPOT);
+ // Calculate the rank map for F.
+ BuildRankMap(F);
MadeChange = false;
- for (BasicBlock *BI : RPOT) {
- // Use a worklist to keep track of which instructions have been processed
- // (and which insts won't be optimized again) so when redoing insts,
- // optimize insts rightaway which won't be processed later.
- SmallSet<Instruction *, 8> Worklist;
-
- // Insert all instructions in the BB
- for (Instruction &I : *BI)
- Worklist.insert(&I);
-
+ for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
// Optimize every instruction in the basic block.
- for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;) {
- // This instruction has been processed.
- Worklist.erase(&*II);
+ for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;)
if (isInstructionTriviallyDead(&*II)) {
EraseInst(&*II++);
} else {
@@ -2202,22 +2187,27 @@ PreservedAnalyses ReassociatePass::run(F
++II;
}
- // If the above optimizations produced new instructions to optimize or
- // made modifications which need to be redone, do them now if they won't
- // be handled later.
- while (!RedoInsts.empty()) {
- Instruction *I = RedoInsts.pop_back_val();
- // Process instructions that won't be processed later, either
- // inside the block itself or in another basic block (based on rank),
- // since these will be processed later.
- if ((I->getParent() != BI || !Worklist.count(I)) &&
- RankMap[I->getParent()] <= RankMap[BI]) {
- if (isInstructionTriviallyDead(I))
- EraseInst(I);
- else
- OptimizeInst(I);
- }
- }
+ // Make a copy of all the instructions to be redone so we can remove dead
+ // instructions.
+ SetVector<AssertingVH<Instruction>> ToRedo(RedoInsts);
+ // Iterate over all instructions to be reevaluated and remove trivially dead
+ // instructions. If any operand of the trivially dead instruction becomes
+ // dead mark it for deletion as well. Continue this process until all
+ // trivially dead instructions have been removed.
+ while (!ToRedo.empty()) {
+ Instruction *I = ToRedo.pop_back_val();
+ if (isInstructionTriviallyDead(I))
+ RecursivelyEraseDeadInsts(I, ToRedo);
+ }
+
+ // Now that we have removed dead instructions, we can reoptimize the
+ // remaining instructions.
+ while (!RedoInsts.empty()) {
+ Instruction *I = RedoInsts.pop_back_val();
+ if (isInstructionTriviallyDead(I))
+ EraseInst(I);
+ else
+ OptimizeInst(I);
}
}
Removed: llvm/trunk/test/Transforms/Reassociate/prev_insts_canonicalized.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/prev_insts_canonicalized.ll?rev=278937&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Reassociate/prev_insts_canonicalized.ll (original)
+++ llvm/trunk/test/Transforms/Reassociate/prev_insts_canonicalized.ll (removed)
@@ -1,57 +0,0 @@
-; RUN: opt < %s -reassociate -S | FileCheck %s
-
-; These tests make sure that before processing insts
-; any previous instructions are already canonicalized.
-define i32 @foo(i32 %in) {
-; CHECK-LABEL: @foo
-; CHECK-NEXT: %factor = mul i32 %in, -4
-; CHECK-NEXT: %factor1 = mul i32 %in, 2
-; CHECK-NEXT: %_3 = add i32 %factor, 1
-; CHECK-NEXT: %_5 = add i32 %_3, %factor1
-; CHECK-NEXT: ret i32 %_5
- %_0 = add i32 %in, 1
- %_1 = mul i32 %in, -2
- %_2 = add i32 %_0, %_1
- %_3 = add i32 %_1, %_2
- %_4 = add i32 %_3, 1
- %_5 = add i32 %in, %_3
- ret i32 %_5
-}
-
-; CHECK-LABEL: @foo1
-define void @foo1(float %in, i1 %cmp) {
-wrapper_entry:
- br label %foo1
-
-for.body:
- %0 = fadd float %in1, %in1
- br label %foo1
-
-foo1:
- %_0 = fmul fast float %in, -3.000000e+00
- %_1 = fmul fast float %_0, 3.000000e+00
- %in1 = fadd fast float -3.000000e+00, %_1
- %in1use = fadd fast float %in1, %in1
- br label %for.body
-
-
-}
-
-; CHECK-LABEL: @foo2
-define void @foo2(float %in, i1 %cmp) {
-wrapper_entry:
- br label %for.body
-
-for.body:
-; If the operands of the phi are sheduled for processing before
-; foo1 is processed, the invariant of reassociate are not preserved
- %unused = phi float [%in1, %foo1], [undef, %wrapper_entry]
- br label %foo1
-
-foo1:
- %_0 = fmul fast float %in, -3.000000e+00
- %_1 = fmul fast float %_0, 3.000000e+00
- %in1 = fadd fast float -3.000000e+00, %_1
- %in1use = fadd fast float %in1, %in1
- br label %for.body
-}
Modified: llvm/trunk/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll?rev=278938&r1=278937&r2=278938&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll (original)
+++ llvm/trunk/test/Transforms/Reassociate/reassoc-intermediate-fnegs.ll Wed Aug 17 10:54:39 2016
@@ -1,8 +1,8 @@
; RUN: opt < %s -reassociate -S | FileCheck %s
; CHECK-LABEL: faddsubAssoc1
-; CHECK: [[TMP1:%.*]] = fsub fast half 0xH8000, %a
-; CHECK: [[TMP2:%.*]] = fadd fast half %b, [[TMP1]]
-; CHECK: fmul fast half [[TMP2]], 0xH4500
+; CHECK: [[TMP1:%tmp.*]] = fmul fast half %a, 0xH4500
+; CHECK: [[TMP2:%tmp.*]] = fmul fast half %b, 0xH4500
+; CHECK: fsub fast half [[TMP2]], [[TMP1]]
; CHECK: ret
; Input is A op (B op C)
define half @faddsubAssoc1(half %a, half %b) {
Modified: llvm/trunk/test/Transforms/Reassociate/xor_reassoc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/xor_reassoc.ll?rev=278938&r1=278937&r2=278938&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Reassociate/xor_reassoc.ll (original)
+++ llvm/trunk/test/Transforms/Reassociate/xor_reassoc.ll Wed Aug 17 10:54:39 2016
@@ -88,8 +88,8 @@ define i32 @xor_special2(i32 %x, i32 %y)
%xor1 = xor i32 %xor, %and
ret i32 %xor1
; CHECK-LABEL: @xor_special2(
-; CHECK: %xor = xor i32 %y, 123
-; CHECK: %xor1 = xor i32 %xor, %x
+; CHECK: %xor = xor i32 %x, 123
+; CHECK: %xor1 = xor i32 %xor, %y
; CHECK: ret i32 %xor1
}
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