[llvm] [VPlan] Reuse mask of immediate dominator in VPlanPredicator (PR #185595)

[Luke Lau via llvm-commits]

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@@ -325,14 +322,7 @@ define void @multiple_blocks_with_dead_inst_multiple_successors_6(ptr %src, i1 %
 ; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <vscale x 8 x i64> poison, i64 [[TMP16]], i64 0
 ; CHECK-NEXT:    [[DOTSPLAT:%.*]] = shufflevector <vscale x 8 x i64> [[DOTSPLATINSERT]], <vscale x 8 x i64> poison, <vscale x 8 x i32> zeroinitializer
 ; CHECK-NEXT:    [[TMP20:%.*]] = getelementptr i16, ptr [[SRC]], <vscale x 8 x i64> [[VEC_IND]]
-; CHECK-NEXT:    [[WIDE_MASKED_GATHER:%.*]] = call <vscale x 8 x i16> @llvm.vp.gather.nxv8i16.nxv8p0(<vscale x 8 x ptr> align 2 [[TMP20]], <vscale x 8 x i1> splat (i1 true), i32 [[TMP27]])
-; CHECK-NEXT:    [[TMP17:%.*]] = icmp eq <vscale x 8 x i16> [[WIDE_MASKED_GATHER]], zeroinitializer
-; CHECK-NEXT:    [[TMP14:%.*]] = select <vscale x 8 x i1> [[TMP17]], <vscale x 8 x i1> [[TMP8]], <vscale x 8 x i1> zeroinitializer
-; CHECK-NEXT:    [[TMP28:%.*]] = xor <vscale x 8 x i1> [[TMP17]], splat (i1 true)
-; CHECK-NEXT:    [[TMP22:%.*]] = or <vscale x 8 x i1> [[TMP14]], [[TMP28]]
-; CHECK-NEXT:    [[TMP23:%.*]] = select <vscale x 8 x i1> [[TMP17]], <vscale x 8 x i1> [[BROADCAST_SPLAT]], <vscale x 8 x i1> zeroinitializer
-; CHECK-NEXT:    [[TMP24:%.*]] = or <vscale x 8 x i1> [[TMP22]], [[TMP23]]
-; CHECK-NEXT:    call void @llvm.vp.scatter.nxv8i16.nxv8p0(<vscale x 8 x i16> zeroinitializer, <vscale x 8 x ptr> align 2 [[TMP20]], <vscale x 8 x i1> [[TMP24]], i32 [[TMP27]])
+; CHECK-NEXT:    call void @llvm.vp.scatter.nxv8i16.nxv8p0(<vscale x 8 x i16> zeroinitializer, <vscale x 8 x ptr> align 2 [[TMP20]], <vscale x 8 x i1> splat (i1 true), i32 [[TMP27]])
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lukel97 wrote:

I think this is a strided store with a stride of 3*2=6 bytes, because we have the `mul i64 3, stepvector` in the preheader feeding in to the gep

https://github.com/llvm/llvm-project/pull/185595