[llvm-branch-commits] [llvm] 39e6d24 - [NewPM] Only non-trivially loop unswitch at -O3 and for non-optsize functions
Arthur Eubanks via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed Jan 13 15:01:27 PST 2021
Author: Arthur Eubanks
Date: 2021-01-13T14:54:49-08:00
New Revision: 39e6d242378a0b645abbdfc6c02de5ef8dcfb9ed
URL: https://github.com/llvm/llvm-project/commit/39e6d242378a0b645abbdfc6c02de5ef8dcfb9ed
DIFF: https://github.com/llvm/llvm-project/commit/39e6d242378a0b645abbdfc6c02de5ef8dcfb9ed.diff
LOG: [NewPM] Only non-trivially loop unswitch at -O3 and for non-optsize functions
This matches the legacy pipeline/pass.
Reviewed By: asbirlea, SjoerdMeijer
Differential Revision: https://reviews.llvm.org/D94559
Added:
Modified:
llvm/lib/Passes/PassBuilder.cpp
llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
llvm/test/Transforms/SimpleLoopUnswitch/ARM/nontrivial-unswitch-cost.ll
llvm/test/Transforms/SimpleLoopUnswitch/pipeline.ll
Removed:
################################################################################
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 0d7f442f9ff4..7b2100aef081 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -724,7 +724,8 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
LPM1.addPass(LoopRotatePass(Level != OptimizationLevel::Oz));
// TODO: Investigate promotion cap for O1.
LPM1.addPass(LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap));
- LPM1.addPass(SimpleLoopUnswitchPass(/* NonTrivial */ true));
+ LPM1.addPass(
+ SimpleLoopUnswitchPass(/* NonTrivial */ Level == OptimizationLevel::O3));
LPM2.addPass(LoopIdiomRecognizePass());
LPM2.addPass(IndVarSimplifyPass());
diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
index 945476a2bdaf..3125f6274848 100644
--- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -2906,6 +2906,10 @@ static bool unswitchLoop(Loop &L, DominatorTree &DT, LoopInfo &LI,
if (!NonTrivial && !EnableNonTrivialUnswitch)
return false;
+ // Skip non-trivial unswitching for optsize functions.
+ if (L.getHeader()->getParent()->hasOptSize())
+ return false;
+
// For non-trivial unswitching, because it often creates new loops, we rely on
// the pass manager to iterate on the loops rather than trying to immediately
// reach a fixed point. There is no substantial advantage to iterating
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/ARM/nontrivial-unswitch-cost.ll b/llvm/test/Transforms/SimpleLoopUnswitch/ARM/nontrivial-unswitch-cost.ll
index 87f52c01e955..8482adec807c 100644
--- a/llvm/test/Transforms/SimpleLoopUnswitch/ARM/nontrivial-unswitch-cost.ll
+++ b/llvm/test/Transforms/SimpleLoopUnswitch/ARM/nontrivial-unswitch-cost.ll
@@ -111,33 +111,19 @@ loop_exit:
define void @test_unswitch_minsize(i1* %ptr, i1 %cond) #0 {
; CHECK-LABEL: @test_unswitch_minsize(
; CHECK-NEXT: entry:
-; CHECK-NEXT: br i1 [[COND:%.*]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
-; CHECK: entry.split.us:
-; CHECK-NEXT: br label [[LOOP_BEGIN_US:%.*]]
-; CHECK: loop_begin.us:
-; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_A_US:%.*]]
-; CHECK: loop_a.us:
-; CHECK-NEXT: call void @a()
-; CHECK-NEXT: br label [[LOOP_LATCH_US:%.*]]
-; CHECK: loop_latch.us:
-; CHECK-NEXT: [[V_US:%.*]] = load i1, i1* [[PTR:%.*]], align 1
-; CHECK-NEXT: br i1 [[V_US]], label [[LOOP_BEGIN_US]], label [[LOOP_EXIT_SPLIT_US:%.*]]
-; CHECK: loop_exit.split.us:
-; CHECK-NEXT: br label [[LOOP_EXIT:%.*]]
-; CHECK: entry.split:
; CHECK-NEXT: br label [[LOOP_BEGIN:%.*]]
; CHECK: loop_begin:
; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_B:%.*]]
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[LOOP_A:%.*]], label [[LOOP_B:%.*]]
+; CHECK: loop_a:
+; CHECK-NEXT: call void @a()
+; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
; CHECK: loop_b:
; CHECK-NEXT: call void @b()
-; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
+; CHECK-NEXT: br label [[LOOP_LATCH]]
; CHECK: loop_latch:
-; CHECK-NEXT: [[V:%.*]] = load i1, i1* [[PTR]], align 1
-; CHECK-NEXT: br i1 [[V]], label [[LOOP_BEGIN]], label [[LOOP_EXIT_SPLIT:%.*]]
-; CHECK: loop_exit.split:
-; CHECK-NEXT: br label [[LOOP_EXIT]]
+; CHECK-NEXT: [[V:%.*]] = load i1, i1* [[PTR:%.*]], align 1
+; CHECK-NEXT: br i1 [[V]], label [[LOOP_BEGIN]], label [[LOOP_EXIT:%.*]]
; CHECK: loop_exit:
; CHECK-NEXT: ret void
;
@@ -235,39 +221,25 @@ loop_exit:
define void @test_unswitch_non_dup_code_minsize(i1* %ptr, i1 %cond) #0 {
; CHECK-LABEL: @test_unswitch_non_dup_code_minsize(
; CHECK-NEXT: entry:
-; CHECK-NEXT: br i1 [[COND:%.*]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
-; CHECK: entry.split.us:
-; CHECK-NEXT: br label [[LOOP_BEGIN_US:%.*]]
-; CHECK: loop_begin.us:
+; CHECK-NEXT: br label [[LOOP_BEGIN:%.*]]
+; CHECK: loop_begin:
; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_A_US:%.*]]
-; CHECK: loop_a.us:
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[LOOP_A:%.*]], label [[LOOP_B:%.*]]
+; CHECK: loop_a:
; CHECK-NEXT: call void @a()
; CHECK-NEXT: call void @a()
; CHECK-NEXT: call void @a()
; CHECK-NEXT: call void @a()
-; CHECK-NEXT: br label [[LOOP_LATCH_US:%.*]]
-; CHECK: loop_latch.us:
-; CHECK-NEXT: [[V_US:%.*]] = load i1, i1* [[PTR:%.*]], align 1
-; CHECK-NEXT: br i1 [[V_US]], label [[LOOP_BEGIN_US]], label [[LOOP_EXIT_SPLIT_US:%.*]]
-; CHECK: loop_exit.split.us:
-; CHECK-NEXT: br label [[LOOP_EXIT:%.*]]
-; CHECK: entry.split:
-; CHECK-NEXT: br label [[LOOP_BEGIN:%.*]]
-; CHECK: loop_begin:
-; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_B:%.*]]
+; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
; CHECK: loop_b:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
-; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
+; CHECK-NEXT: br label [[LOOP_LATCH]]
; CHECK: loop_latch:
-; CHECK-NEXT: [[V:%.*]] = load i1, i1* [[PTR]], align 1
-; CHECK-NEXT: br i1 [[V]], label [[LOOP_BEGIN]], label [[LOOP_EXIT_SPLIT:%.*]]
-; CHECK: loop_exit.split:
-; CHECK-NEXT: br label [[LOOP_EXIT]]
+; CHECK-NEXT: [[V:%.*]] = load i1, i1* [[PTR:%.*]], align 1
+; CHECK-NEXT: br i1 [[V]], label [[LOOP_BEGIN]], label [[LOOP_EXIT:%.*]]
; CHECK: loop_exit:
; CHECK-NEXT: ret void
;
@@ -387,45 +359,31 @@ loop_exit:
define void @test_unswitch_non_dup_code_in_cfg_minsize(i1* %ptr, i1 %cond) #0 {
; CHECK-LABEL: @test_unswitch_non_dup_code_in_cfg_minsize(
; CHECK-NEXT: entry:
-; CHECK-NEXT: br i1 [[COND:%.*]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
-; CHECK: entry.split.us:
-; CHECK-NEXT: br label [[LOOP_BEGIN_US:%.*]]
-; CHECK: loop_begin.us:
-; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_A_US:%.*]]
-; CHECK: loop_a.us:
-; CHECK-NEXT: [[V1_US:%.*]] = load i1, i1* [[PTR:%.*]], align 1
-; CHECK-NEXT: br i1 [[V1_US]], label [[LOOP_A_A_US:%.*]], label [[LOOP_A_B_US:%.*]]
-; CHECK: loop_a_b.us:
-; CHECK-NEXT: call void @a()
-; CHECK-NEXT: br label [[LOOP_LATCH_US:%.*]]
-; CHECK: loop_a_a.us:
-; CHECK-NEXT: call void @a()
-; CHECK-NEXT: br label [[LOOP_LATCH_US]]
-; CHECK: loop_latch.us:
-; CHECK-NEXT: [[V3_US:%.*]] = load i1, i1* [[PTR]], align 1
-; CHECK-NEXT: br i1 [[V3_US]], label [[LOOP_BEGIN_US]], label [[LOOP_EXIT_SPLIT_US:%.*]]
-; CHECK: loop_exit.split.us:
-; CHECK-NEXT: br label [[LOOP_EXIT:%.*]]
-; CHECK: entry.split:
; CHECK-NEXT: br label [[LOOP_BEGIN:%.*]]
; CHECK: loop_begin:
; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_B:%.*]]
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[LOOP_A:%.*]], label [[LOOP_B:%.*]]
+; CHECK: loop_a:
+; CHECK-NEXT: [[V1:%.*]] = load i1, i1* [[PTR:%.*]], align 1
+; CHECK-NEXT: br i1 [[V1]], label [[LOOP_A_A:%.*]], label [[LOOP_A_B:%.*]]
+; CHECK: loop_a_a:
+; CHECK-NEXT: call void @a()
+; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
+; CHECK: loop_a_b:
+; CHECK-NEXT: call void @a()
+; CHECK-NEXT: br label [[LOOP_LATCH]]
; CHECK: loop_b:
; CHECK-NEXT: [[V2:%.*]] = load i1, i1* [[PTR]], align 1
; CHECK-NEXT: br i1 [[V2]], label [[LOOP_B_A:%.*]], label [[LOOP_B_B:%.*]]
; CHECK: loop_b_a:
; CHECK-NEXT: call void @b()
-; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
+; CHECK-NEXT: br label [[LOOP_LATCH]]
; CHECK: loop_b_b:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: br label [[LOOP_LATCH]]
; CHECK: loop_latch:
; CHECK-NEXT: [[V3:%.*]] = load i1, i1* [[PTR]], align 1
-; CHECK-NEXT: br i1 [[V3]], label [[LOOP_BEGIN]], label [[LOOP_EXIT_SPLIT:%.*]]
-; CHECK: loop_exit.split:
-; CHECK-NEXT: br label [[LOOP_EXIT]]
+; CHECK-NEXT: br i1 [[V3]], label [[LOOP_BEGIN]], label [[LOOP_EXIT:%.*]]
; CHECK: loop_exit:
; CHECK-NEXT: ret void
;
@@ -666,31 +624,22 @@ loop_exit:
define void @test_unswitch_dedicated_exiting_minsize(i1* %ptr, i1 %cond) #0 {
; CHECK-LABEL: @test_unswitch_dedicated_exiting_minsize(
; CHECK-NEXT: entry:
-; CHECK-NEXT: br i1 [[COND:%.*]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
-; CHECK: entry.split.us:
-; CHECK-NEXT: br label [[LOOP_BEGIN_US:%.*]]
-; CHECK: loop_begin.us:
-; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_A_US:%.*]]
-; CHECK: loop_a.us:
-; CHECK-NEXT: call void @a()
-; CHECK-NEXT: br label [[LOOP_LATCH_US:%.*]]
-; CHECK: loop_latch.us:
-; CHECK-NEXT: [[V_US:%.*]] = load i1, i1* [[PTR:%.*]], align 1
-; CHECK-NEXT: br i1 [[V_US]], label [[LOOP_BEGIN_US]], label [[LOOP_EXIT_SPLIT_US:%.*]]
-; CHECK: loop_exit.split.us:
-; CHECK-NEXT: br label [[LOOP_EXIT:%.*]]
-; CHECK: entry.split:
; CHECK-NEXT: br label [[LOOP_BEGIN:%.*]]
; CHECK: loop_begin:
; CHECK-NEXT: call void @x()
-; CHECK-NEXT: br label [[LOOP_B_EXIT:%.*]]
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[LOOP_A:%.*]], label [[LOOP_B_EXIT:%.*]]
+; CHECK: loop_a:
+; CHECK-NEXT: call void @a()
+; CHECK-NEXT: br label [[LOOP_LATCH:%.*]]
; CHECK: loop_b_exit:
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
; CHECK-NEXT: call void @b()
; CHECK-NEXT: ret void
+; CHECK: loop_latch:
+; CHECK-NEXT: [[V:%.*]] = load i1, i1* [[PTR:%.*]], align 1
+; CHECK-NEXT: br i1 [[V]], label [[LOOP_BEGIN]], label [[LOOP_EXIT:%.*]]
; CHECK: loop_exit:
; CHECK-NEXT: ret void
;
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/pipeline.ll b/llvm/test/Transforms/SimpleLoopUnswitch/pipeline.ll
index 953b407cccd9..186a65876911 100644
--- a/llvm/test/Transforms/SimpleLoopUnswitch/pipeline.ll
+++ b/llvm/test/Transforms/SimpleLoopUnswitch/pipeline.ll
@@ -1,12 +1,15 @@
-; RUN: opt < %s -S -passes="default<O1>" | FileCheck %s -check-prefix=O1
-; RUN: opt < %s -S -passes="default<O2>" | FileCheck %s -check-prefix=O2
+; RUN: opt < %s -S -passes="default<O1>" | FileCheck %s -check-prefixes=TRIVIAL,CHECK
+; RUN: opt < %s -S -passes="default<O2>" | FileCheck %s -check-prefixes=TRIVIAL,CHECK
+; RUN: opt < %s -S -passes="default<O3>" | FileCheck %s -check-prefixes=NONTRIVIAL,CHECK
+; RUN: opt < %s -S -passes="default<Os>" | FileCheck %s -check-prefixes=TRIVIAL,CHECK
+; RUN: opt < %s -S -passes="default<Oz>" | FileCheck %s -check-prefixes=TRIVIAL,CHECK
declare i32 @a()
declare i32 @b()
declare i32 @c()
-; O1-NOT: loop_begin.us:
-; O2: loop_begin.us:
+; TRIVIAL-NOT: loop_begin.us:
+; NONTRIVIAL: loop_begin.us:
define i32 @test1(i1* %ptr, i1 %cond1, i1 %cond2) {
entry:
@@ -37,3 +40,34 @@ latch:
loop_exit:
ret i32 0
}
+
+; CHECK-NOT: loop2_begin.us:
+define i32 @test2(i1* %ptr, i1 %cond1, i1 %cond2) optsize {
+entry:
+ br label %loop2_begin
+
+loop2_begin:
+ br i1 %cond1, label %loop2_a, label %loop2_b
+
+loop2_a:
+ call i32 @a()
+ br label %latch2
+
+loop2_b:
+ br i1 %cond2, label %loop2_b_a, label %loop2_b_b
+
+loop2_b_a:
+ call i32 @b()
+ br label %latch2
+
+loop2_b_b:
+ call i32 @c()
+ br label %latch2
+
+latch2:
+ %v = load i1, i1* %ptr
+ br i1 %v, label %loop2_begin, label %loop2_exit
+
+loop2_exit:
+ ret i32 0
+}
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