From dfd447c22043b0a64bf1d146735ca33f926bd22d Mon Sep 17 00:00:00 2001 From: David Stenberg Date: Thu, 20 Aug 2020 08:28:24 +0200 Subject: [PATCH] [LoopUnswitch] Fix incorrect Modified status When hoisting simple values out from a loop, and an optsize attribute, a convergent call, or an invoke instruction hindered the pass from unswitching the loop, the pass would return an incorrect Modified status. This was caught using the check introduced by D80916. Reviewed By: asbirlea Differential Revision: https://reviews.llvm.org/D86085 --- llvm/lib/Transforms/Scalar/LoopUnswitch.cpp | 6 +-- .../LoopUnswitch/convergent-hoist-modified.ll | 42 +++++++++++++++++ .../LoopUnswitch/invoke-hoist-modified.ll | 53 ++++++++++++++++++++++ .../LoopUnswitch/optsize-hoist-modified.ll | 39 ++++++++++++++++ 4 files changed, 137 insertions(+), 3 deletions(-) create mode 100644 llvm/test/Transforms/LoopUnswitch/convergent-hoist-modified.ll create mode 100644 llvm/test/Transforms/LoopUnswitch/invoke-hoist-modified.ll create mode 100644 llvm/test/Transforms/LoopUnswitch/optsize-hoist-modified.ll diff --git a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp index 645a89b..d83b7b0 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -661,7 +661,7 @@ bool LoopUnswitch::processCurrentLoop() { // FIXME: Use Function::hasOptSize(). if (OptimizeForSize || LoopHeader->getParent()->hasFnAttribute(Attribute::OptimizeForSize)) - return false; + return Changed; // Run through the instructions in the loop, keeping track of three things: // @@ -685,10 +685,10 @@ bool LoopUnswitch::processCurrentLoop() { if (!CB) continue; if (CB->isConvergent()) - return false; + return Changed; if (auto *II = dyn_cast(&I)) if (!II->getUnwindDest()->canSplitPredecessors()) - return false; + return Changed; if (auto *II = dyn_cast(&I)) if (II->getIntrinsicID() == Intrinsic::experimental_guard) Guards.push_back(II); diff --git a/llvm/test/Transforms/LoopUnswitch/convergent-hoist-modified.ll b/llvm/test/Transforms/LoopUnswitch/convergent-hoist-modified.ll new file mode 100644 index 0000000..bb77f4c --- /dev/null +++ b/llvm/test/Transforms/LoopUnswitch/convergent-hoist-modified.ll @@ -0,0 +1,42 @@ +; RUN: opt -loop-unswitch -enable-new-pm=0 %s -S | FileCheck %s + +; When hoisting simple values out from a loop, and not being able to unswitch +; the loop due to the convergent call, the pass would return an incorrect +; Modified status. This was caught by the pass return status check that is +; hidden under EXPENSIVE_CHECKS. + +; CHECK-LABEL: entry: +; CHECK-NEXT: %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) +; CHECK-NEXT: %1 = icmp uge i32 %0, 1 +; CHECK-NEXT: br label %for.cond + +%struct.anon = type { i16 } + +@b = global %struct.anon zeroinitializer, align 1 + +; Function Attrs: nounwind +define i16 @c() #0 { +entry: + br label %for.cond + +for.cond: ; preds = %cont, %entry + br label %for.inc + +for.inc: ; preds = %for.cond + %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) + %1 = icmp uge i32 %0, 1 + br i1 %1, label %cont, label %cont + +cont: ; preds = %for.inc + call void @conv() convergent + %2 = load i16, i16* getelementptr inbounds (%struct.anon, %struct.anon* @b, i32 0, i32 0), align 1 + br label %for.cond +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare i32 @llvm.objectsize.i32.p0i8(i8*, i1 immarg, i1 immarg, i1 immarg) #1 + +declare void @conv() convergent + +attributes #0 = { nounwind } +attributes #1 = { nounwind readnone speculatable willreturn } diff --git a/llvm/test/Transforms/LoopUnswitch/invoke-hoist-modified.ll b/llvm/test/Transforms/LoopUnswitch/invoke-hoist-modified.ll new file mode 100644 index 0000000..367bae2 --- /dev/null +++ b/llvm/test/Transforms/LoopUnswitch/invoke-hoist-modified.ll @@ -0,0 +1,53 @@ +; RUN: opt -loop-unswitch -enable-new-pm=0 %s -S | FileCheck %s + +; When hoisting simple values out from a loop, and not being able to unswitch +; the loop due to the invoke instruction, the pass would return an incorrect +; Modified status. This was caught by the pass return status check that is +; hidden under EXPENSIVE_CHECKS. + +; CHECK-LABEL: for.cond: +; CHECK-NEXT: %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) +; CHECK-NEXT: %1 = icmp uge i32 %0, 1 +; CHECK-NEXT: br label %for.inc + +%struct.anon = type { i16 } + +@b = global %struct.anon zeroinitializer, align 1 + +; Function Attrs: nounwind +define i32 @c() #0 personality i32 (...)* @__CxxFrameHandler3 { +entry: + br label %for.cond + +for.cond: ; preds = %cont, %entry + br label %for.inc + +for.inc: ; preds = %for.cond + %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) + %1 = icmp uge i32 %0, 1 + br i1 %1, label %delete.notnull, label %delete.notnull + +delete.notnull: ; preds = %for.inc + invoke void @g() to label %invoke.cont unwind label %lpad + +invoke.cont: ; preds = %delete.notnull + br label %for.inc + +lpad: ; preds = %delete.notnull + %cp = cleanuppad within none [] + cleanupret from %cp unwind to caller + +cont: ; preds = %for.inc + %2 = load i16, i16* getelementptr inbounds (%struct.anon, %struct.anon* @b, i32 0, i32 0), align 1 + br label %for.cond +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare i32 @llvm.objectsize.i32.p0i8(i8*, i1 immarg, i1 immarg, i1 immarg) #1 + +declare void @g() + +declare i32 @__CxxFrameHandler3(...) + +attributes #0 = { nounwind } +attributes #1 = { nounwind readnone speculatable willreturn } diff --git a/llvm/test/Transforms/LoopUnswitch/optsize-hoist-modified.ll b/llvm/test/Transforms/LoopUnswitch/optsize-hoist-modified.ll new file mode 100644 index 0000000..9ec1f40 --- /dev/null +++ b/llvm/test/Transforms/LoopUnswitch/optsize-hoist-modified.ll @@ -0,0 +1,39 @@ +; RUN: opt -loop-unswitch -enable-new-pm=0 %s -S | FileCheck %s + +; When hoisting simple values out from a loop, and not being able to attempt to +; non-trivally unswitch the loop, due to the optsize attribute, the pass would +; return an incorrect Modified status. This was caught by the pass return +; status check that is hidden under EXPENSIVE_CHECKS. + +; CHECK-LABEL: entry: +; CHECK-NEXT: %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) +; CHECK-NEXT: %1 = icmp uge i32 %0, 1 +; CHECK-NEXT: br label %for.cond + +%struct.anon = type { i16 } + +@b = global %struct.anon zeroinitializer, align 1 + +; Function Attrs: minsize nounwind optsize +define i16 @c() #0 { +entry: + br label %for.cond + +for.cond: ; preds = %cont, %entry + br label %for.inc + +for.inc: ; preds = %for.cond + %0 = call i32 @llvm.objectsize.i32.p0i8(i8* bitcast (%struct.anon* @b to i8*), i1 false, i1 false, i1 false) + %1 = icmp uge i32 %0, 1 + br i1 %1, label %cont, label %cont + +cont: ; preds = %for.inc + %2 = load i16, i16* getelementptr inbounds (%struct.anon, %struct.anon* @b, i32 0, i32 0), align 1 + br label %for.cond +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare i32 @llvm.objectsize.i32.p0i8(i8*, i1 immarg, i1 immarg, i1 immarg) #1 + +attributes #0 = { minsize nounwind optsize } +attributes #1 = { nounwind readnone speculatable willreturn } -- 2.7.4