https://github.com/mtrofin updated https://github.com/llvm/llvm-project/pull/164271
>From 0a768f01ce410e4d1ee377442246a5f7f0442494 Mon Sep 17 00:00:00 2001 From: Mircea Trofin <[email protected]> Date: Mon, 20 Oct 2025 08:21:26 -0700 Subject: [PATCH] [SLU][profcheck] create likely branch weights for guard->branch --- .../Transforms/Scalar/SimpleLoopUnswitch.cpp | 12 ++++++--- .../Transforms/SimpleLoopUnswitch/guards.ll | 26 ++++++++++++------- 2 files changed, 25 insertions(+), 13 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp index 239526e85e1fd..86b2090081ed0 100644 --- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp +++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp @@ -40,6 +40,7 @@ #include "llvm/IR/Instruction.h" #include "llvm/IR/Instructions.h" #include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/MDBuilder.h" #include "llvm/IR/Module.h" #include "llvm/IR/PatternMatch.h" #include "llvm/IR/ProfDataUtils.h" @@ -2831,9 +2832,14 @@ static BranchInst *turnGuardIntoBranch(IntrinsicInst *GI, Loop &L, MSSAU->getMemorySSA()->verifyMemorySSA(); DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager); - Instruction *DeoptBlockTerm = - SplitBlockAndInsertIfThen(GI->getArgOperand(0), GI, true, - GI->getMetadata(LLVMContext::MD_prof), &DTU, &LI); + // llvm.experimental.guard doesn't have branch weights. We can assume, + // however, that the deopt path is unlikely. + Instruction *DeoptBlockTerm = SplitBlockAndInsertIfThen( + GI->getArgOperand(0), GI, true, + !ProfcheckDisableMetadataFixes && EstimateProfile + ? MDBuilder(GI->getContext()).createUnlikelyBranchWeights() + : nullptr, + &DTU, &LI); BranchInst *CheckBI = cast<BranchInst>(CheckBB->getTerminator()); // SplitBlockAndInsertIfThen inserts control flow that branches to // DeoptBlockTerm if the condition is true. We want the opposite. diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/guards.ll b/llvm/test/Transforms/SimpleLoopUnswitch/guards.ll index 706b49df14749..42b32e769d8d7 100644 --- a/llvm/test/Transforms/SimpleLoopUnswitch/guards.ll +++ b/llvm/test/Transforms/SimpleLoopUnswitch/guards.ll @@ -1,15 +1,15 @@ -; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 5 ; RUN: opt -passes='loop(simple-loop-unswitch<nontrivial>),verify<loops>' -simple-loop-unswitch-guards -S < %s | FileCheck %s ; RUN: opt -passes='simple-loop-unswitch<nontrivial>' -simple-loop-unswitch-guards -S < %s | FileCheck %s ; RUN: opt -passes='loop-mssa(simple-loop-unswitch<nontrivial>),verify<loops>' -simple-loop-unswitch-guards -verify-memoryssa -verify-loop-info -S < %s | FileCheck %s declare void @llvm.experimental.guard(i1, ...) -define void @test_simple_case(i1 %cond, i32 %N) { +define void @test_simple_case(i1 %cond, i32 %N) !prof !0 { ; CHECK-LABEL: define void @test_simple_case( -; CHECK-SAME: i1 [[COND:%.*]], i32 [[N:%.*]]) { +; CHECK-SAME: i1 [[COND:%.*]], i32 [[N:%.*]]) !prof [[PROF0:![0-9]+]] { ; CHECK-NEXT: [[ENTRY:.*:]] -; CHECK-NEXT: br i1 [[COND]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]], !prof [[PROF1:![0-9]+]] ; CHECK: [[ENTRY_SPLIT_US]]: ; CHECK-NEXT: br label %[[LOOP_US:.*]] ; CHECK: [[LOOP_US]]: @@ -50,9 +50,9 @@ define void @test_two_guards(i1 %cond1, i1 %cond2, i32 %N) { ; CHECK-LABEL: define void @test_two_guards( ; CHECK-SAME: i1 [[COND1:%.*]], i1 [[COND2:%.*]], i32 [[N:%.*]]) { ; CHECK-NEXT: [[ENTRY:.*:]] -; CHECK-NEXT: br i1 [[COND1]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND1]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[ENTRY_SPLIT_US]]: -; CHECK-NEXT: br i1 [[COND2]], label %[[ENTRY_SPLIT_US_SPLIT_US:.*]], label %[[ENTRY_SPLIT_US_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND2]], label %[[ENTRY_SPLIT_US_SPLIT_US:.*]], label %[[ENTRY_SPLIT_US_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[ENTRY_SPLIT_US_SPLIT_US]]: ; CHECK-NEXT: br label %[[LOOP_US_US:.*]] ; CHECK: [[LOOP_US_US]]: @@ -108,7 +108,7 @@ define void @test_conditional_guards(i1 %cond, i32 %N) { ; CHECK-SAME: i1 [[COND:%.*]], i32 [[N:%.*]]) { ; CHECK-NEXT: [[ENTRY:.*:]] ; CHECK-NEXT: [[COND_FR:%.*]] = freeze i1 [[COND]] -; CHECK-NEXT: br i1 [[COND_FR]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND_FR]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[ENTRY_SPLIT_US]]: ; CHECK-NEXT: br label %[[LOOP_US:.*]] ; CHECK: [[LOOP_US]]: @@ -171,7 +171,7 @@ define void @test_nested_loop(i1 %cond, i32 %N, i1 %arg) { ; CHECK-LABEL: define void @test_nested_loop( ; CHECK-SAME: i1 [[COND:%.*]], i32 [[N:%.*]], i1 [[ARG:%.*]]) { ; CHECK-NEXT: [[ENTRY:.*:]] -; CHECK-NEXT: br i1 [[COND]], label %[[ENTRY_SPLIT:.*]], label %[[OUTER_LOOP_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND]], label %[[ENTRY_SPLIT:.*]], label %[[OUTER_LOOP_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[ENTRY_SPLIT]]: ; CHECK-NEXT: br i1 [[ARG]], label %[[ENTRY_SPLIT_SPLIT_US:.*]], label %[[ENTRY_SPLIT_SPLIT:.*]] ; CHECK: [[ENTRY_SPLIT_SPLIT_US]]: @@ -243,7 +243,7 @@ define void @test_sibling_loops(i1 %cond1, i1 %cond2, i32 %N) { ; CHECK-LABEL: define void @test_sibling_loops( ; CHECK-SAME: i1 [[COND1:%.*]], i1 [[COND2:%.*]], i32 [[N:%.*]]) { ; CHECK-NEXT: [[ENTRY:.*:]] -; CHECK-NEXT: br i1 [[COND1]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND1]], label %[[ENTRY_SPLIT_US:.*]], label %[[ENTRY_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[ENTRY_SPLIT_US]]: ; CHECK-NEXT: br label %[[LOOP1_US:.*]] ; CHECK: [[LOOP1_US]]: @@ -263,7 +263,7 @@ define void @test_sibling_loops(i1 %cond1, i1 %cond2, i32 %N) { ; CHECK-NEXT: call void (i1, ...) @llvm.experimental.guard(i1 false) [ "deopt"() ] ; CHECK-NEXT: unreachable ; CHECK: [[BETWEEN]]: -; CHECK-NEXT: br i1 [[COND2]], label %[[BETWEEN_SPLIT_US2:.*]], label %[[BETWEEN_SPLIT:.*]] +; CHECK-NEXT: br i1 [[COND2]], label %[[BETWEEN_SPLIT_US2:.*]], label %[[BETWEEN_SPLIT:.*]], !prof [[PROF1]] ; CHECK: [[BETWEEN_SPLIT_US2]]: ; CHECK-NEXT: br label %[[LOOP2_US:.*]] ; CHECK: [[LOOP2_US]]: @@ -343,3 +343,9 @@ exit: declare void @may_throw(i32 %i) declare i32 @__CxxFrameHandler3(...) + +!0 = !{!"function_entry_count", i32 10} +;. +; CHECK: [[PROF0]] = !{!"function_entry_count", i32 10} +; CHECK: [[PROF1]] = !{!"branch_weights", i32 1048575, i32 1} +;. _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
