[llvm] e066993 - [LoopUnroll] Disable loop unroll when user explicitly asks for unroll-and-jam

Zaara Syeda via llvm-commits llvm-commits at lists.llvm.org
Wed Dec 15 07:58:20 PST 2021


Author: Zaara Syeda
Date: 2021-12-15T15:58:05Z
New Revision: e0669931afdb3f11f1f1e359482372ae5f3c8cd5

URL: https://github.com/llvm/llvm-project/commit/e0669931afdb3f11f1f1e359482372ae5f3c8cd5
DIFF: https://github.com/llvm/llvm-project/commit/e0669931afdb3f11f1f1e359482372ae5f3c8cd5.diff

LOG: [LoopUnroll] Disable loop unroll when user explicitly asks for unroll-and-jam

If a loop isn't forced to be unrolled, we want to avoid unrolling it when there
is an explicit unroll-and-jam pragma. This is to prevent automatic unrolling
from interfering with the user requested transformation.
Missed adding the testcase in earlier commit.

Differential Revision: https://reviews.llvm.org/D114886

Added: 
    llvm/test/Transforms/LoopUnrollAndJam/pragma-disable-unroll.ll

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/LoopUnrollAndJam/pragma-disable-unroll.ll b/llvm/test/Transforms/LoopUnrollAndJam/pragma-disable-unroll.ll
new file mode 100644
index 0000000000000..59c63473638b8
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnrollAndJam/pragma-disable-unroll.ll
@@ -0,0 +1,94 @@
+; RUN: opt -loop-unroll -debug-only=loop-unroll -S < %s  2>&1 | FileCheck %s
+; REQUIRES: asserts
+
+
+; CHECK: Loop Unroll: F[test]
+; CHECK-NEXT: Not unrolling loop since parent loop has llvm.loop.unroll_and_jam
+; CHECK: Loop Unroll: F[test]
+; CHECK-NEXT: Not unrolling loop since it has llvm.loop.unroll_and_jam
+
+define i32 @test() {
+for.body4.preheader.preheader:
+  br label %for.body4.preheader4
+
+for.body4.preheader4:                             ; preds = %for.cond.cleanup3, %for.body4.preheader.preheader
+  %indvars.iv28 = phi i64 [ %indvars.iv.next29, %for.cond.cleanup3 ], [ 0, %for.body4.preheader.preheader ]
+  br label %for.body4
+
+for.body4:                                        ; preds = %for.body4.preheader4, %for.body4
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body4 ], [ 0, %for.body4.preheader4 ]
+  tail call void @test2(i64 %indvars.iv28, i64 %indvars.iv)
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv.next, 10
+  br i1 %exitcond.not, label %for.cond.cleanup3, label %for.body4
+
+for.cond.cleanup3:                                ; preds = %for.body4
+  %indvars.iv.next29 = add nuw nsw i64 %indvars.iv28, 1
+  %exitcond31.not = icmp eq i64 %indvars.iv.next29, 10
+  br i1 %exitcond31.not, label %for.cond.cleanup, label %for.body4.preheader4, !llvm.loop !1
+
+for.cond.cleanup:                                 ; preds = %for.cond.cleanup3
+  ret i32 55
+}
+
+
+; CHECK: F[test_02]
+; CHECK-NOT: Not unrolling loop since {{.*}}  llvm.loop.unroll_and_jam
+define i32 @test_02() {
+for.body4.preheader.preheader:
+  br label %for.body4.preheader4
+
+for.body4.preheader4:                             ; preds = %for.cond.cleanup3, %for.body4.preheader.preheader
+  %indvars.iv28 = phi i64 [ %indvars.iv.next29, %for.cond.cleanup3 ], [ 0, %for.body4.preheader.preheader ]
+  br label %for.body4
+
+for.body4:                                        ; preds = %for.body4.preheader4, %for.body4
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body4 ], [ 0, %for.body4.preheader4 ]
+  tail call void @test2(i64 %indvars.iv28, i64 %indvars.iv)
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv.next, 10
+  br i1 %exitcond.not, label %for.cond.cleanup3, label %for.body4
+
+for.cond.cleanup3:                                ; preds = %for.body4
+  %indvars.iv.next29 = add nuw nsw i64 %indvars.iv28, 1
+  %exitcond31.not = icmp eq i64 %indvars.iv.next29, 10
+  br i1 %exitcond31.not, label %for.cond.cleanup, label %for.body4.preheader4, !llvm.loop !2
+
+for.cond.cleanup:                                 ; preds = %for.cond.cleanup3
+  ret i32 55
+}
+
+; CHECK:F[test_03]
+; CHECK-NOT: Not unrolling loop since {{.*}}  llvm.loop.unroll_and_jam
+define i32 @test_03() {
+for.body4.preheader.preheader:
+  br label %for.body4.preheader4
+
+for.body4.preheader4:                             ; preds = %for.cond.cleanup3, %for.body4.preheader.preheader
+  %indvars.iv28 = phi i64 [ %indvars.iv.next29, %for.cond.cleanup3 ], [ 0, %for.body4.preheader.preheader ]
+  br label %for.body4
+
+for.body4:                                        ; preds = %for.body4.preheader4, %for.body4
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body4 ], [ 0, %for.body4.preheader4 ]
+  tail call void @test2(i64 %indvars.iv28, i64 %indvars.iv)
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv.next, 10
+  br i1 %exitcond.not, label %for.cond.cleanup3, label %for.body4
+
+for.cond.cleanup3:                                ; preds = %for.body4
+  %indvars.iv.next29 = add nuw nsw i64 %indvars.iv28, 1
+  %exitcond31.not = icmp eq i64 %indvars.iv.next29, 10
+  br i1 %exitcond31.not, label %for.cond.cleanup, label %for.body4.preheader4, !llvm.loop !3
+
+for.cond.cleanup:                                 ; preds = %for.cond.cleanup3
+  ret i32 55
+}
+
+declare void @test2(i64 signext, i64 signext)
+
+!1 = distinct !{!1, !4}
+!2 = distinct !{!1, !5}
+!3 = distinct !{!1, !6}
+!4 = !{!"llvm.loop.unroll_and_jam.count", i32 4}
+!5 = !{!"llvm.loop.unroll_and_jam.count", i32 1}
+!6 = !{!"llvm.loop.unroll_and_jam.disable"}


        


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