[LV] Fix PR33613 - retain order of insertelement per part

r306381 caused PR33613, by reversing the order in which insertelements were
generated per unroll part. This patch fixes PR33613 by retraining this order,
placing each set of insertelements per part immediately after the last scalar
being packed for this part. Includes a test case derived from PR33613.

Reference: https://bugs.llvm.org/show_bug.cgi?id=33613
Differential Revision: https://reviews.llvm.org/D34760

llvm-svn: 306575

1 files changed, 55 insertions, 4 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll b/llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
index 3d1c78038e3..ef65deee8ec 100644
--- a/llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
+++ b/llvm/test/Transforms/LoopVectorize/first-order-recurrence.ll
@@ -295,14 +295,14 @@ for.cond.cleanup3:
 ; UNROLL-NO-IC-NEXT:    [[TMP28:%.*]] = load i32, i32* {{.*}}
 ; UNROLL-NO-IC-NEXT:    [[TMP29:%.*]] = load i32, i32* {{.*}}
 ; UNROLL-NO-IC-NEXT:    [[TMP30:%.*]] = load i32, i32* {{.*}}
-; UNROLL-NO-IC-NEXT:    [[TMP31:%.*]] = load i32, i32* {{.*}}
-; UNROLL-NO-IC-NEXT:    [[TMP32:%.*]] = load i32, i32* {{.*}}
-; UNROLL-NO-IC-NEXT:    [[TMP33:%.*]] = load i32, i32* {{.*}}
-; UNROLL-NO-IC-NEXT:    [[TMP34:%.*]] = load i32, i32* {{.*}}
 ; UNROLL-NO-IC-NEXT:    [[TMP35:%.*]] = insertelement <4 x i32> undef, i32 [[TMP27]], i32 0
 ; UNROLL-NO-IC-NEXT:    [[TMP36:%.*]] = insertelement <4 x i32> [[TMP35]], i32 [[TMP28]], i32 1
 ; UNROLL-NO-IC-NEXT:    [[TMP37:%.*]] = insertelement <4 x i32> [[TMP36]], i32 [[TMP29]], i32 2
 ; UNROLL-NO-IC-NEXT:    [[TMP38:%.*]] = insertelement <4 x i32> [[TMP37]], i32 [[TMP30]], i32 3
+; UNROLL-NO-IC-NEXT:    [[TMP31:%.*]] = load i32, i32* {{.*}}
+; UNROLL-NO-IC-NEXT:    [[TMP32:%.*]] = load i32, i32* {{.*}}
+; UNROLL-NO-IC-NEXT:    [[TMP33:%.*]] = load i32, i32* {{.*}}
+; UNROLL-NO-IC-NEXT:    [[TMP34:%.*]] = load i32, i32* {{.*}}
 ; UNROLL-NO-IC-NEXT:    [[TMP39:%.*]] = insertelement <4 x i32> undef, i32 [[TMP31]], i32 0
 ; UNROLL-NO-IC-NEXT:    [[TMP40:%.*]] = insertelement <4 x i32> [[TMP39]], i32 [[TMP32]], i32 1
 ; UNROLL-NO-IC-NEXT:    [[TMP41:%.*]] = insertelement <4 x i32> [[TMP40]], i32 [[TMP33]], i32 2
@@ -396,3 +396,54 @@ for.body:
 for.end:
   ret i32 %val.phi
 }
+
+; We vectorize this first order recurrence, with a set of insertelements for
+; each unrolled part. Make sure these insertelements are generated in-order,
+; because the shuffle of the first order recurrence will be added after the
+; insertelement of the last part UF - 1, assuming the latter appears after the
+; insertelements of all other parts.
+;
+; int PR33613(double *b, double j, int d) {
+;   int a = 0;
+;   for(int i = 0; i < 10240; i++, b+=25) {
+;     double f = b[d]; // Scalarize to form insertelements
+;     if (j * f)
+;       a++;
+;     j = f;
+;   }
+;   return a;
+; }
+;
+; UNROLL-NO-IC-LABEL: @PR33613(
+; UNROLL-NO-IC:     vector.body:
+; UNROLL-NO-IC:       [[VECTOR_RECUR:%.*]] = phi <4 x double>
+; UNROLL-NO-IC:       shufflevector <4 x double> [[VECTOR_RECUR]], <4 x double> {{.*}}, <4 x i32> <i32 3, i32 4, i32 5, i32 6>
+; UNROLL-NO-IC-NEXT:  shufflevector <4 x double> {{.*}}, <4 x double> {{.*}}, <4 x i32> <i32 3, i32 4, i32 5, i32 6>
+; UNROLL-NO-IC-NOT:   insertelement <4 x double>
+; UNROLL-NO-IC:     middle.block:
+;
+define i32 @PR33613(double* %b, double %j, i32 %d) {
+entry:
+  %idxprom = sext i32 %d to i64
+  br label %for.body
+
+for.cond.cleanup:
+  %a.1.lcssa = phi i32 [ %a.1, %for.body ]
+  ret i32 %a.1.lcssa
+
+for.body:
+  %b.addr.012 = phi double* [ %b, %entry ], [ %add.ptr, %for.body ]
+  %i.011 = phi i32 [ 0, %entry ], [ %inc1, %for.body ]
+  %a.010 = phi i32 [ 0, %entry ], [ %a.1, %for.body ]
+  %j.addr.09 = phi double [ %j, %entry ], [ %0, %for.body ]
+  %arrayidx = getelementptr inbounds double, double* %b.addr.012, i64 %idxprom
+  %0 = load double, double* %arrayidx, align 8
+  %mul = fmul double %j.addr.09, %0
+  %tobool = fcmp une double %mul, 0.000000e+00
+  %inc = zext i1 %tobool to i32
+  %a.1 = add nsw i32 %a.010, %inc
+  %inc1 = add nuw nsw i32 %i.011, 1
+  %add.ptr = getelementptr inbounds double, double* %b.addr.012, i64 25
+  %exitcond = icmp eq i32 %inc1, 10240
+  br i1 %exitcond, label %for.cond.cleanup, label %for.body
+}