diff options
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll b/llvm/test/Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll new file mode 100644 index 00000000000..40af8f3adf0 --- /dev/null +++ b/llvm/test/Transforms/LoopVectorize/pr30654-phiscev-sext-trunc.ll @@ -0,0 +1,240 @@ +; RUN: opt -S -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 < %s 2>&1 | FileCheck %s + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + +; Check that the vectorizer identifies the %p.09 phi, +; as an induction variable, despite the potential overflow +; due to the truncation from 32bit to 8bit. +; SCEV will detect the pattern "sext(trunc(%p.09)) + %step" +; and generate the required runtime checks under which +; we can assume no overflow. We check here that we generate +; exactly two runtime checks: +; 1) an overflow check: +; {0,+,(trunc i32 %step to i8)}<%for.body> Added Flags: <nssw> +; 2) an equality check verifying that the step of the induction +; is equal to sext(trunc(step)): +; Equal predicate: %step == (sext i8 (trunc i32 %step to i8) to i32) +; +; See also pr30654. +; +; int a[N]; +; void doit1(int n, int step) { +; int i; +; char p = 0; +; for (i = 0; i < n; i++) { +; a[i] = p; +; p = p + step; +; } +; } +; + +; CHECK-LABEL: @doit1 +; CHECK: vector.scevcheck +; CHECK: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: %[[TEST:[0-9]+]] = or i1 {{.*}}, %mul.overflow +; CHECK: %[[NTEST:[0-9]+]] = or i1 false, %[[TEST]] +; CHECK: %ident.check = icmp ne i32 {{.*}}, %{{.*}} +; CHECK: %{{.*}} = or i1 %[[NTEST]], %ident.check +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: vector.body: +; CHECK: <4 x i32> + +@a = common local_unnamed_addr global [250 x i32] zeroinitializer, align 16 + +; Function Attrs: norecurse nounwind uwtable +define void @doit1(i32 %n, i32 %step) local_unnamed_addr { +entry: + %cmp7 = icmp sgt i32 %n, 0 + br i1 %cmp7, label %for.body.preheader, label %for.end + +for.body.preheader: + %wide.trip.count = zext i32 %n to i64 + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] + %p.09 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ] + %sext = shl i32 %p.09, 24 + %conv = ashr exact i32 %sext, 24 + %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv + store i32 %conv, i32* %arrayidx, align 4 + %add = add nsw i32 %conv, %step + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count + br i1 %exitcond, label %for.end.loopexit, label %for.body + +for.end.loopexit: + br label %for.end + +for.end: + ret void +} + +; Same as above, but for checking the SCEV "zext(trunc(%p.09)) + %step". +; Here we expect the following two predicates to be added for runtime checking: +; 1) {0,+,(trunc i32 %step to i8)}<%for.body> Added Flags: <nusw> +; 2) Equal predicate: %step == (zext i8 (trunc i32 %step to i8) to i32) +; +; int a[N]; +; void doit2(int n, int step) { +; int i; +; unsigned char p = 0; +; for (i = 0; i < n; i++) { +; a[i] = p; +; p = p + step; +; } +; } +; + +; CHECK-LABEL: @doit2 +; CHECK: vector.scevcheck +; CHECK: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: %[[TEST:[0-9]+]] = or i1 {{.*}}, %mul.overflow +; CHECK: %[[NTEST:[0-9]+]] = or i1 false, %[[TEST]] +; CHECK: %ident.check = icmp ne i32 {{.*}}, %{{.*}} +; CHECK: %{{.*}} = or i1 %[[NTEST]], %ident.check +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: vector.body: +; CHECK: <4 x i32> + +; Function Attrs: norecurse nounwind uwtable +define void @doit2(i32 %n, i32 %step) local_unnamed_addr { +entry: + %cmp7 = icmp sgt i32 %n, 0 + br i1 %cmp7, label %for.body.preheader, label %for.end + +for.body.preheader: + %wide.trip.count = zext i32 %n to i64 + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] + %p.09 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ] + %conv = and i32 %p.09, 255 + %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv + store i32 %conv, i32* %arrayidx, align 4 + %add = add nsw i32 %conv, %step + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count + br i1 %exitcond, label %for.end.loopexit, label %for.body + +for.end.loopexit: + br label %for.end + +for.end: + ret void +} + +; Here we check that the same phi scev analysis would fail +; to create the runtime checks because the step is not invariant. +; As a result vectorization will fail. +; +; int a[N]; +; void doit3(int n, int step) { +; int i; +; char p = 0; +; for (i = 0; i < n; i++) { +; a[i] = p; +; p = p + step; +; step += 2; +; } +; } +; + +; CHECK-LABEL: @doit3 +; CHECK-NOT: vector.scevcheck +; CHECK-NOT: vector.body: +; CHECK-LABEL: for.body: + +; Function Attrs: norecurse nounwind uwtable +define void @doit3(i32 %n, i32 %step) local_unnamed_addr { +entry: + %cmp9 = icmp sgt i32 %n, 0 + br i1 %cmp9, label %for.body.preheader, label %for.end + +for.body.preheader: + %wide.trip.count = zext i32 %n to i64 + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] + %p.012 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ] + %step.addr.010 = phi i32 [ %add3, %for.body ], [ %step, %for.body.preheader ] + %sext = shl i32 %p.012, 24 + %conv = ashr exact i32 %sext, 24 + %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv + store i32 %conv, i32* %arrayidx, align 4 + %add = add nsw i32 %conv, %step.addr.010 + %add3 = add nsw i32 %step.addr.010, 2 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count + br i1 %exitcond, label %for.end.loopexit, label %for.body + +for.end.loopexit: + br label %for.end + +for.end: + ret void +} + + +; Lastly, we also check the case where we can tell at compile time that +; the step of the induction is equal to sext(trunc(step)), in which case +; we don't have to check this equality at runtime (we only need the +; runtime overflow check). Therefore only the following overflow predicate +; will be added for runtime checking: +; {0,+,%cstep}<%for.body> Added Flags: <nssw> +; +; a[N]; +; void doit4(int n, char cstep) { +; int i; +; char p = 0; +; int istep = cstep; +; for (i = 0; i < n; i++) { +; a[i] = p; +; p = p + istep; +; } +; } + +; CHECK-LABEL: @doit4 +; CHECK: vector.scevcheck +; CHECK: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: %{{.*}} = or i1 {{.*}}, %mul.overflow +; CHECK-NOT: %ident.check = icmp ne i32 {{.*}}, %{{.*}} +; CHECK-NOT: %{{.*}} = or i1 %{{.*}}, %ident.check +; CHECK-NOT: %mul = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 {{.*}}, i8 {{.*}}) +; CHECK: vector.body: +; CHECK: <4 x i32> + +; Function Attrs: norecurse nounwind uwtable +define void @doit4(i32 %n, i8 signext %cstep) local_unnamed_addr { +entry: + %conv = sext i8 %cstep to i32 + %cmp10 = icmp sgt i32 %n, 0 + br i1 %cmp10, label %for.body.preheader, label %for.end + +for.body.preheader: + %wide.trip.count = zext i32 %n to i64 + br label %for.body + +for.body: + %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %for.body.preheader ] + %p.011 = phi i32 [ %add, %for.body ], [ 0, %for.body.preheader ] + %sext = shl i32 %p.011, 24 + %conv2 = ashr exact i32 %sext, 24 + %arrayidx = getelementptr inbounds [250 x i32], [250 x i32]* @a, i64 0, i64 %indvars.iv + store i32 %conv2, i32* %arrayidx, align 4 + %add = add nsw i32 %conv2, %conv + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count + br i1 %exitcond, label %for.end.loopexit, label %for.body + +for.end.loopexit: + br label %for.end + +for.end: + ret void +} |
