[PATCH] D119148: [LoopUnroll] Always respect user unroll pragma

[Whitney Tsang via Phabricator via llvm-commits]

Whitney updated this revision to Diff 406502.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D119148/new/

https://reviews.llvm.org/D119148

Files:
  llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
  llvm/test/Transforms/LoopUnroll/unroll-pragmas.ll


Index: llvm/test/Transforms/LoopUnroll/unroll-pragmas.ll
===================================================================
--- llvm/test/Transforms/LoopUnroll/unroll-pragmas.ll
+++ llvm/test/Transforms/LoopUnroll/unroll-pragmas.ll
@@ -235,33 +235,6 @@
 !10 = !{!10, !11}
 !11 = !{!"llvm.loop.unroll.count", i32 1}
 
-; #pragma clang loop unroll(full)
-; Loop has very high loop count (1 million) and full unrolling was requested.
-; Loop should unrolled up to the pragma threshold, but not completely.
-;
-; CHECK-LABEL: @unroll_1M(
-; CHECK: store i32
-; CHECK: store i32
-; CHECK: br i1
-define void @unroll_1M(i32* nocapture %a, i32 %b) {
-entry:
-  br label %for.body
-
-for.body:                                         ; preds = %for.body, %entry
-  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
-  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
-  %0 = load i32, 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
-  %exitcond = icmp eq i64 %indvars.iv.next, 1000000
-  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !12
-
-for.end:                                          ; preds = %for.body
-  ret void
-}
-!12 = !{!12, !4}
-
 ; #pragma clang loop unroll(enable)
 ; Loop should be fully unrolled.
 ;
Index: llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -788,14 +788,12 @@
 
   // 2nd priority is unroll count set by pragma.
   if (PInfo.PragmaCount > 0) {
-    if ((UP.AllowRemainder || (TripMultiple % PInfo.PragmaCount == 0)) &&
-        UCE.getUnrolledLoopSize(UP, PInfo.PragmaCount) < PragmaUnrollThreshold)
+    if ((UP.AllowRemainder || (TripMultiple % PInfo.PragmaCount == 0)))
       return PInfo.PragmaCount;
   }
 
   if (PInfo.PragmaFullUnroll && TripCount != 0) {
-    if (UCE.getUnrolledLoopSize(UP, TripCount) < PragmaUnrollThreshold)
-      return TripCount;
+    return TripCount;
   }
   // if didn't return until here, should continue to other priorties
   return None;


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