[llvm] r213789 - Do not add unroll disable metadata after unrolling pass for loops with #pragma clang loop unroll(full).
Mark Heffernan
meheff at google.com
Wed Jul 23 13:05:44 PDT 2014
Author: meheff
Date: Wed Jul 23 15:05:44 2014
New Revision: 213789
URL: http://llvm.org/viewvc/llvm-project?rev=213789&view=rev
Log:
Do not add unroll disable metadata after unrolling pass for loops with #pragma clang loop unroll(full).
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=213789&r1=213788&r2=213789&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp Wed Jul 23 15:05:44 2014
@@ -457,9 +457,10 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPa
}
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.
Modified: llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll?rev=213789&r1=213788&r2=213789&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll (original)
+++ llvm/trunk/test/Transforms/LoopUnroll/unroll-pragmas-disabled.ll Wed Jul 23 15:05:44 2014
@@ -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:
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:
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:.*]]}
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