[LV] Introduce VPBlendRecipe, VPWidenMemoryInstructionRecipe

This patch is part of D38676.

The patch introduces two new Recipes to handle instructions whose vectorization
involves masking. These Recipes take VPlan-level masks in D38676, but still rely
on ILV's existing createEdgeMask(), createBlockInMask() in this patch.

VPBlendRecipe handles intra-loop phi nodes, which are vectorized as a sequence
of SELECTs. Its execute() code is refactored out of ILV::widenPHIInstruction(),
which now handles only loop-header phi nodes.

VPWidenMemoryInstructionRecipe handles load/store which are to be widened
(but are not part of an Interleave Group). In this patch it simply calls
ILV::vectorizeMemoryInstruction on execute().

Differential Revision: https://reviews.llvm.org/D39068

llvm-svn: 318149

1 files changed, 38 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/X86/x86-predication.ll b/llvm/test/Transforms/LoopVectorize/X86/x86-predication.ll
index b35fc59542b..45d843c9d58 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/x86-predication.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/x86-predication.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -mattr=avx -force-vector-width=2 -force-vector-interleave=1 -loop-vectorize -simplifycfg -S | FileCheck %s
+; RUN: opt -mcpu=skylake-avx512 -S -force-vector-width=8 -force-vector-interleave=1 -loop-vectorize < %s | FileCheck %s --check-prefix=SINK-GATHER
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.8.0"
@@ -58,3 +59,40 @@ for.end:
   %tmp8 = phi i32 [ %tmp7, %for.inc ]
   ret i32 %tmp8
 }
+
+; This test ensures that a load, which would have been widened otherwise is
+; instead scalarized if Cost-Model so decided as part of its
+; sink-scalar-operands optimization for predicated instructions.
+;
+; SINK-GATHER: vector.body:
+; SINK-GATHER: pred.udiv.if:
+; SINK-GATHER:   %[[T0:.+]] = load i32, i32* %{{.*}}, align 4
+; SINK-GATHER:   %{{.*}} = udiv i32 %[[T0]], %{{.*}}
+; SINK-GATHER: pred.udiv.continue:
+define i32 @scalarize_and_sink_gather(i32* %a, i1 %c, i32 %x, i64 %n) {
+entry:
+  br label %for.body
+
+for.body:
+  %i = phi i64 [ 0, %entry ], [ %i.next, %for.inc ]
+  %r = phi i32 [ 0, %entry ], [ %tmp6, %for.inc ]
+  %i7 = mul i64 %i, 777
+  br i1 %c, label %if.then, label %for.inc
+
+if.then:
+  %tmp0 = getelementptr inbounds i32, i32* %a, i64 %i7
+  %tmp2 = load i32, i32* %tmp0, align 4
+  %tmp4 = udiv i32 %tmp2, %x
+  br label %for.inc
+
+for.inc:
+  %tmp5 = phi i32 [ %x, %for.body ], [ %tmp4, %if.then]
+  %tmp6 = add i32 %r, %tmp5
+  %i.next = add nuw nsw i64 %i, 1
+  %cond = icmp slt i64 %i.next, %n
+  br i1 %cond, label %for.body, label %for.end
+
+for.end:
+  %tmp7 = phi i32 [ %tmp6, %for.inc ]
+  ret i32 %tmp7
+}