diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp | 15 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/AArch64/unroll-optsize.ll | 171 |
2 files changed, 184 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp index c113e4d3166..53015d25842 100644 --- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -207,6 +207,7 @@ TargetTransformInfo::UnrollingPreferences llvm::gatherUnrollingPreferences( if (OptForSize) { UP.Threshold = UP.OptSizeThreshold; UP.PartialThreshold = UP.PartialOptSizeThreshold; + UP.MaxPercentThresholdBoost = 100; } // Apply any user values specified by cl::opt @@ -993,6 +994,7 @@ static LoopUnrollResult tryToUnrollLoop( if (OnlyWhenForced && !(TM & TM_Enable)) return LoopUnrollResult::Unmodified; + bool OptForSize = L->getHeader()->getParent()->hasOptSize(); unsigned NumInlineCandidates; bool NotDuplicatable; bool Convergent; @@ -1000,8 +1002,11 @@ static LoopUnrollResult tryToUnrollLoop( L, SE, TTI, BFI, PSI, OptLevel, ProvidedThreshold, ProvidedCount, ProvidedAllowPartial, ProvidedRuntime, ProvidedUpperBound, ProvidedAllowPeeling); - // Exit early if unrolling is disabled. - if (UP.Threshold == 0 && (!UP.Partial || UP.PartialThreshold == 0)) + + // Exit early if unrolling is disabled. For OptForSize, we pick the loop size + // as threshold later on. + if (UP.Threshold == 0 && (!UP.Partial || UP.PartialThreshold == 0) && + !OptForSize) return LoopUnrollResult::Unmodified; SmallPtrSet<const Value *, 32> EphValues; @@ -1016,6 +1021,12 @@ static LoopUnrollResult tryToUnrollLoop( << " instructions.\n"); return LoopUnrollResult::Unmodified; } + + // When optimizing for size, use LoopSize as threshold, to (fully) unroll + // loops, if it does not increase code size. + if (OptForSize) + UP.Threshold = std::max(UP.Threshold, LoopSize); + if (NumInlineCandidates != 0) { LLVM_DEBUG(dbgs() << " Not unrolling loop with inlinable calls.\n"); return LoopUnrollResult::Unmodified; diff --git a/llvm/test/Transforms/LoopUnroll/AArch64/unroll-optsize.ll b/llvm/test/Transforms/LoopUnroll/AArch64/unroll-optsize.ll new file mode 100644 index 00000000000..c0bf00b938a --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/AArch64/unroll-optsize.ll @@ -0,0 +1,171 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -loop-unroll -mtriple=arm64-apple-iphoneos -S %s | FileCheck %s + +; Check we unroll even with optsize, if the result is smaller, either because +; we have single iteration loops or bodies with constant folding opportunities +; after fully unrolling. + +declare i32 @get() + +define void @fully_unrolled_single_iteration(i32* %src) #0 { +; CHECK-LABEL: @fully_unrolled_single_iteration( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[ARR:%.*]] = alloca [4 x i32], align 4 +; CHECK-NEXT: br label [[FOR_BODY:%.*]] +; CHECK: for.body: +; CHECK-NEXT: [[V:%.*]] = load i32, i32* [[SRC:%.*]] +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 0 +; CHECK-NEXT: store i32 [[V]], i32* [[ARRAYIDX]], align 4 +; CHECK-NEXT: [[PTR:%.*]] = bitcast [4 x i32]* [[ARR]] to i32* +; CHECK-NEXT: call void @use(i32* nonnull [[PTR]]) +; CHECK-NEXT: ret void +; +entry: + %arr = alloca [4 x i32], align 4 + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %src.idx = getelementptr inbounds i32, i32* %src, i64 %indvars.iv + %v = load i32, i32* %src.idx + %arrayidx = getelementptr inbounds [4 x i32], [4 x i32]* %arr, i64 0, i64 %indvars.iv + store i32 %v, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, 1 + br i1 %exitcond, label %for.cond.cleanup, label %for.body + +for.cond.cleanup: ; preds = %for.cond + %ptr = bitcast [4 x i32]* %arr to i32* + call void @use(i32* nonnull %ptr) #4 + ret void +} + + +define void @fully_unrolled_smaller() #0 { +; CHECK-LABEL: @fully_unrolled_smaller( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[ARR:%.*]] = alloca [4 x i32], align 4 +; CHECK-NEXT: br label [[FOR_BODY:%.*]] +; CHECK: for.body: +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 0 +; CHECK-NEXT: store i32 16, i32* [[ARRAYIDX]], align 4 +; CHECK-NEXT: [[ARRAYIDX_1:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 1 +; CHECK-NEXT: store i32 4104, i32* [[ARRAYIDX_1]], align 4 +; CHECK-NEXT: [[ARRAYIDX_2:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 2 +; CHECK-NEXT: store i32 1048592, i32* [[ARRAYIDX_2]], align 4 +; CHECK-NEXT: [[ARRAYIDX_3:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 3 +; CHECK-NEXT: store i32 268435480, i32* [[ARRAYIDX_3]], align 4 +; CHECK-NEXT: [[PTR:%.*]] = bitcast [4 x i32]* [[ARR]] to i32* +; CHECK-NEXT: call void @use(i32* nonnull [[PTR]]) +; CHECK-NEXT: ret void +; +entry: + %arr = alloca [4 x i32], align 4 + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %indvars.iv.tr = trunc i64 %indvars.iv to i32 + %shl.0 = shl i32 %indvars.iv.tr, 3 + %shl.1 = shl i32 16, %shl.0 + %or = or i32 %shl.1, %shl.0 + %arrayidx = getelementptr inbounds [4 x i32], [4 x i32]* %arr, i64 0, i64 %indvars.iv + store i32 %or, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 3 + br i1 %exitcond, label %for.cond.cleanup, label %for.body + +for.cond.cleanup: ; preds = %for.cond + %ptr = bitcast [4 x i32]* %arr to i32* + call void @use(i32* nonnull %ptr) #4 + ret void +} + +define void @fully_unrolled_smaller_Oz() #1 { +; CHECK-LABEL: @fully_unrolled_smaller_Oz( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[ARR:%.*]] = alloca [4 x i32], align 4 +; CHECK-NEXT: br label [[FOR_BODY:%.*]] +; CHECK: for.body: +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 0 +; CHECK-NEXT: store i32 16, i32* [[ARRAYIDX]], align 4 +; CHECK-NEXT: [[ARRAYIDX_1:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 1 +; CHECK-NEXT: store i32 4104, i32* [[ARRAYIDX_1]], align 4 +; CHECK-NEXT: [[ARRAYIDX_2:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 2 +; CHECK-NEXT: store i32 1048592, i32* [[ARRAYIDX_2]], align 4 +; CHECK-NEXT: [[ARRAYIDX_3:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 3 +; CHECK-NEXT: store i32 268435480, i32* [[ARRAYIDX_3]], align 4 +; CHECK-NEXT: [[PTR:%.*]] = bitcast [4 x i32]* [[ARR]] to i32* +; CHECK-NEXT: call void @use(i32* nonnull [[PTR]]) +; CHECK-NEXT: ret void +; +entry: + %arr = alloca [4 x i32], align 4 + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %indvars.iv.tr = trunc i64 %indvars.iv to i32 + %shl.0 = shl i32 %indvars.iv.tr, 3 + %shl.1 = shl i32 16, %shl.0 + %or = or i32 %shl.1, %shl.0 + %arrayidx = getelementptr inbounds [4 x i32], [4 x i32]* %arr, i64 0, i64 %indvars.iv + store i32 %or, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 3 + br i1 %exitcond, label %for.cond.cleanup, label %for.body + +for.cond.cleanup: ; preds = %for.cond + %ptr = bitcast [4 x i32]* %arr to i32* + call void @use(i32* nonnull %ptr) #4 + ret void +} + + +define void @fully_unrolled_bigger() #0 { +; CHECK-LABEL: @fully_unrolled_bigger( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[ARR:%.*]] = alloca [4 x i32], align 4 +; CHECK-NEXT: br label [[FOR_BODY:%.*]] +; CHECK: for.body: +; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: [[INDVARS_IV_TR:%.*]] = trunc i64 [[INDVARS_IV]] to i32 +; CHECK-NEXT: [[SHL_0:%.*]] = shl i32 [[INDVARS_IV_TR]], 3 +; CHECK-NEXT: [[SHL_1:%.*]] = shl i32 16, [[SHL_0]] +; CHECK-NEXT: [[OR:%.*]] = or i32 [[SHL_1]], [[SHL_0]] +; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [4 x i32], [4 x i32]* [[ARR]], i64 0, i64 [[INDVARS_IV]] +; CHECK-NEXT: store i32 [[OR]], i32* [[ARRAYIDX]], align 4 +; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1 +; CHECK-NEXT: [[EXITCOND:%.*]] = icmp eq i64 [[INDVARS_IV]], 6 +; CHECK-NEXT: br i1 [[EXITCOND]], label [[FOR_COND_CLEANUP:%.*]], label [[FOR_BODY]] +; CHECK: for.cond.cleanup: +; CHECK-NEXT: [[PTR:%.*]] = bitcast [4 x i32]* [[ARR]] to i32* +; CHECK-NEXT: call void @use(i32* nonnull [[PTR]]) +; CHECK-NEXT: ret void +; +entry: + %arr = alloca [4 x i32], align 4 + br label %for.body + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %indvars.iv.tr = trunc i64 %indvars.iv to i32 + %shl.0 = shl i32 %indvars.iv.tr, 3 + %shl.1 = shl i32 16, %shl.0 + %or = or i32 %shl.1, %shl.0 + %arrayidx = getelementptr inbounds [4 x i32], [4 x i32]* %arr, i64 0, i64 %indvars.iv + store i32 %or, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 6 + br i1 %exitcond, label %for.cond.cleanup, label %for.body + +for.cond.cleanup: ; preds = %for.cond + %ptr = bitcast [4 x i32]* %arr to i32* + call void @use(i32* nonnull %ptr) #4 + ret void +} + +declare void @use(i32*) + +attributes #0 = { optsize } +attributes #1 = { minsize optsize } |
