[llvm] 05b4310 - Revert "[Pipelines] Perform hoisting prior to GVN"

[David Green via llvm-commits]

Author: David Green
Date: 2023-08-08T15:32:24+01:00
New Revision: 05b4310c8aec7a050574277ced08a0ab86b27681

URL: https://github.com/llvm/llvm-project/commit/05b4310c8aec7a050574277ced08a0ab86b27681
DIFF: https://github.com/llvm/llvm-project/commit/05b4310c8aec7a050574277ced08a0ab86b27681.diff

LOG: Revert "[Pipelines] Perform hoisting prior to GVN"

This reverts commit 1f37088679a5c2416707d477093950e48148d430 as it causes a
large regression in x264, and some other regressions in downstream embedded
benchmarks under LTO.

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilderPipelines.cpp
    llvm/test/Transforms/PhaseOrdering/gvn-replacement-vs-hoist.ll
    llvm/test/Transforms/PhaseOrdering/loop-rotation-vs-common-code-hoisting.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index a13b5d125d6d61..660cb2e974d781 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -640,9 +640,8 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   FPM.addPass(createFunctionToLoopPassAdaptor(std::move(LPM1),
                                               /*UseMemorySSA=*/true,
                                               /*UseBlockFrequencyInfo=*/true));
-  FPM.addPass(SimplifyCFGPass(
-      SimplifyCFGOptions().hoistCommonInsts(true).convertSwitchRangeToICmp(
-          true)));
+  FPM.addPass(
+      SimplifyCFGPass(SimplifyCFGOptions().convertSwitchRangeToICmp(true)));
   FPM.addPass(InstCombinePass());
   // The loop passes in LPM2 (LoopIdiomRecognizePass, IndVarSimplifyPass,
   // LoopDeletionPass and LoopFullUnrollPass) do not preserve MemorySSA.

diff  --git a/llvm/test/Transforms/PhaseOrdering/gvn-replacement-vs-hoist.ll b/llvm/test/Transforms/PhaseOrdering/gvn-replacement-vs-hoist.ll
index ce67b4f72f09fe..ea863f7355ad9f 100644
--- a/llvm/test/Transforms/PhaseOrdering/gvn-replacement-vs-hoist.ll
+++ b/llvm/test/Transforms/PhaseOrdering/gvn-replacement-vs-hoist.ll
@@ -5,17 +5,26 @@ define void @test(ptr noundef %a, i32 noundef %beam) {
 ; CHECK-LABEL: define void @test
 ; CHECK-SAME: (ptr nocapture noundef writeonly [[A:%.*]], i32 noundef [[BEAM:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] {
 ; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[MUL:%.*]] = shl nuw nsw i32 [[BEAM]], 1
+; CHECK-NEXT:    [[IDXPROM:%.*]] = zext i32 [[MUL]] to i64
+; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[IDXPROM]]
 ; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
 ; CHECK:       for.cond.cleanup:
 ; CHECK-NEXT:    ret void
 ; CHECK:       for.body:
-; CHECK-NEXT:    [[I_06:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY]] ]
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne i32 [[I_06]], [[BEAM]]
-; CHECK-NEXT:    [[MUL:%.*]] = shl nuw nsw i32 [[I_06]], 1
-; CHECK-NEXT:    [[IDXPROM:%.*]] = zext i32 [[MUL]] to i64
-; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[IDXPROM]]
-; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = zext i1 [[CMP1]] to i32
-; CHECK-NEXT:    store i32 [[SPEC_SELECT]], ptr [[ARRAYIDX]], align 4
+; CHECK-NEXT:    [[I_06:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_INC:%.*]] ]
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[I_06]], [[BEAM]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    store i32 0, ptr [[ARRAYIDX]], align 4
+; CHECK-NEXT:    br label [[FOR_INC]]
+; CHECK:       if.else:
+; CHECK-NEXT:    [[MUL2:%.*]] = shl nuw nsw i32 [[I_06]], 1
+; CHECK-NEXT:    [[IDXPROM3:%.*]] = zext i32 [[MUL2]] to i64
+; CHECK-NEXT:    [[ARRAYIDX4:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[IDXPROM3]]
+; CHECK-NEXT:    store i32 1, ptr [[ARRAYIDX4]], align 4
+; CHECK-NEXT:    br label [[FOR_INC]]
+; CHECK:       for.inc:
 ; CHECK-NEXT:    [[INC]] = add nuw nsw i32 [[I_06]], 1
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[I_06]], 9999
 ; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_COND_CLEANUP:%.*]]

diff  --git a/llvm/test/Transforms/PhaseOrdering/loop-rotation-vs-common-code-hoisting.ll b/llvm/test/Transforms/PhaseOrdering/loop-rotation-vs-common-code-hoisting.ll
index f8414c96b7c94f..b5bba73e05f836 100644
--- a/llvm/test/Transforms/PhaseOrdering/loop-rotation-vs-common-code-hoisting.ll
+++ b/llvm/test/Transforms/PhaseOrdering/loop-rotation-vs-common-code-hoisting.ll
@@ -51,8 +51,8 @@ define void @_Z4loopi(i32 %width) {
 ; HOIST-NEXT:    br label [[FOR_COND:%.*]]
 ; HOIST:       for.cond:
 ; HOIST-NEXT:    [[I_0:%.*]] = phi i32 [ [[INC:%.*]], [[FOR_BODY:%.*]] ], [ 0, [[FOR_COND_PREHEADER]] ]
-; HOIST-NEXT:    tail call void @f0()
 ; HOIST-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i32 [[I_0]], [[SUB]]
+; HOIST-NEXT:    tail call void @f0()
 ; HOIST-NEXT:    br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP:%.*]], label [[FOR_BODY]]
 ; HOIST:       for.cond.cleanup:
 ; HOIST-NEXT:    tail call void @f2()