From d55c7c7f42f49aff5c6ff47728552d849518d360 Mon Sep 17 00:00:00 2001 From: Mark Heffernan Date: Wed, 23 Jul 2014 20:05:44 +0000 Subject: [PATCH] Do not add unroll disable metadata after unrolling pass for loops with #pragma clang loop unroll(full). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213789 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopUnrollPass.cpp | 7 ++- .../LoopUnroll/unroll-pragmas-disabled.ll | 60 ++++++++++++++----- 2 files changed, 50 insertions(+), 17 deletions(-) diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp index ff2b8ed267d..2e94a44cad7 100644 --- a/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -457,9 +457,10 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPassManager &LPM) { } if (HasPragma) { - // Mark loop as unrolled to prevent unrolling beyond that - // requested by the pragma. - SetLoopAlreadyUnrolled(L); + if (PragmaCount != 0) + // If loop has an unroll count pragma mark loop as unrolled to prevent + // unrolling beyond that requested by the pragma. + SetLoopAlreadyUnrolled(L); // Emit optimization remarks if we are unable to unroll the loop // as directed by a pragma. diff --git a/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll b/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll index dcde9ebfbbf..04f8f483af0 100644 --- a/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll +++ b/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll @@ -1,14 +1,14 @@ ; RUN: opt < %s -loop-unroll -S | FileCheck %s ; -; Verify that the unrolling pass removes existing loop unrolling metadata +; Verify that the unrolling pass removes existing unroll count metadata ; and adds a disable unrolling node after unrolling is complete. target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" -; #pragma clang loop vectorize(enable) unroll(full) unroll_count(4) vectorize_width(8) +; #pragma clang loop vectorize(enable) unroll_count(4) vectorize_width(8) ; -; Unroll metadata should be replaced with unroll(disable). Vectorize +; Unroll count metadata should be replaced with unroll(disable). Vectorize ; metadata should be untouched. ; ; CHECK-LABEL: @loop1( @@ -30,19 +30,49 @@ for.body: ; preds = %for.body, %entry for.end: ; preds = %for.body ret void } -!1 = metadata !{metadata !1, metadata !2, metadata !3, metadata !4, metadata !5} +!1 = metadata !{metadata !1, metadata !2, metadata !3, metadata !4} !2 = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true} -!3 = metadata !{metadata !"llvm.loop.unroll.full"} -!4 = metadata !{metadata !"llvm.loop.unroll.count", i32 4} -!5 = metadata !{metadata !"llvm.loop.vectorize.width", i32 8} +!3 = metadata !{metadata !"llvm.loop.unroll.count", i32 4} +!4 = metadata !{metadata !"llvm.loop.vectorize.width", i32 8} -; #pragma clang loop unroll(disable) +; #pragma clang loop unroll(full) ; -; Unroll metadata should not change. +; An unroll disable metadata node is only added for the unroll count case. +; In this case, the loop has a full unroll metadata but can't be fully unrolled +; because the trip count is dynamic. The full unroll metadata should remain +; after unrolling. ; ; CHECK-LABEL: @loop2( ; CHECK: br i1 {{.*}}, label {{.*}}, label {{.*}}, !llvm.loop ![[LOOP_2:.*]] -define void @loop2(i32* nocapture %a) { +define void @loop2(i32* nocapture %a, i32 %b) { +entry: + %cmp3 = icmp sgt i32 %b, 0 + br i1 %cmp3, label %for.body, label %for.end, !llvm.loop !5 + +for.body: ; preds = %entry, %for.body + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ] + %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv + %0 = load i32* %arrayidx, align 4 + %inc = add nsw i32 %0, 1 + store i32 %inc, i32* %arrayidx, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %lftr.wideiv = trunc i64 %indvars.iv.next to i32 + %exitcond = icmp eq i32 %lftr.wideiv, %b + br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !5 + +for.end: ; preds = %for.body, %entry + ret void +} +!5 = metadata !{metadata !5, metadata !6} +!6 = metadata !{metadata !"llvm.loop.unroll.full"} + +; #pragma clang loop unroll(disable) +; +; Unroll metadata should not change. +; +; CHECK-LABEL: @loop3( +; CHECK: br i1 {{.*}}, label {{.*}}, label {{.*}}, !llvm.loop ![[LOOP_3:.*]] +define void @loop3(i32* nocapture %a) { entry: br label %for.body @@ -54,16 +84,18 @@ for.body: ; preds = %for.body, %entry store i32 %inc, i32* %arrayidx, align 4 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %exitcond = icmp eq i64 %indvars.iv.next, 64 - br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !6 + br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !7 for.end: ; preds = %for.body ret void } -!6 = metadata !{metadata !6, metadata !7} -!7 = metadata !{metadata !"llvm.loop.unroll.disable"} +!7 = metadata !{metadata !7, metadata !8} +!8 = metadata !{metadata !"llvm.loop.unroll.disable"} ; CHECK: ![[LOOP_1]] = metadata !{metadata ![[LOOP_1]], metadata ![[VEC_ENABLE:.*]], metadata ![[WIDTH_8:.*]], metadata ![[UNROLL_DISABLE:.*]]} ; CHECK: ![[VEC_ENABLE]] = metadata !{metadata !"llvm.loop.vectorize.enable", i1 true} ; CHECK: ![[WIDTH_8]] = metadata !{metadata !"llvm.loop.vectorize.width", i32 8} ; CHECK: ![[UNROLL_DISABLE]] = metadata !{metadata !"llvm.loop.unroll.disable"} -; CHECK: ![[LOOP_2]] = metadata !{metadata ![[LOOP_2]], metadata ![[UNROLL_DISABLE:.*]]} +; CHECK: ![[LOOP_2]] = metadata !{metadata ![[LOOP_2]], metadata ![[UNROLL_FULL:.*]]} +; CHECK: ![[UNROLL_FULL]] = metadata !{metadata !"llvm.loop.unroll.full"} +; CHECK: ![[LOOP_3]] = metadata !{metadata ![[LOOP_3]], metadata ![[UNROLL_DISABLE:.*]]} -- 2.34.1