[LV] Reverse mask up front, not when creating vector pointer.

Reverse mask early on when populating BlockInMask. This will enable
separating mask management and address computation from the memory
recipes in the future and is also needed to enable explicit unrolling in
VPlan.

Pull Request: #72163

Author: fhahn

llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll

@@ -1515,24 +1515,24 @@ define void @foo6(ptr nocapture readonly %in, ptr nocapture %out, i32 %size, ptr
 ; AVX512-NEXT:    [[TMP21:%.*]] = getelementptr double, ptr [[IN]], i64 [[TMP1]]
 ; AVX512-NEXT:    [[TMP22:%.*]] = getelementptr double, ptr [[IN]], i64 [[TMP2]]
 ; AVX512-NEXT:    [[TMP23:%.*]] = getelementptr double, ptr [[IN]], i64 [[TMP3]]
+; AVX512-NEXT:    [[REVERSE12:%.*]] = shufflevector <8 x i1> [[TMP16]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
+; AVX512-NEXT:    [[REVERSE14:%.*]] = shufflevector <8 x i1> [[TMP17]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
+; AVX512-NEXT:    [[REVERSE17:%.*]] = shufflevector <8 x i1> [[TMP18]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
+; AVX512-NEXT:    [[REVERSE20:%.*]] = shufflevector <8 x i1> [[TMP19]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[TMP24:%.*]] = getelementptr double, ptr [[TMP20]], i32 0
 ; AVX512-NEXT:    [[TMP25:%.*]] = getelementptr double, ptr [[TMP24]], i32 -7
-; AVX512-NEXT:    [[REVERSE12:%.*]] = shufflevector <8 x i1> [[TMP16]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[WIDE_MASKED_LOAD:%.*]] = call <8 x double> @llvm.masked.load.v8f64.p0(ptr [[TMP25]], i32 8, <8 x i1> [[REVERSE12]], <8 x double> poison), !alias.scope !34
 ; AVX512-NEXT:    [[REVERSE13:%.*]] = shufflevector <8 x double> [[WIDE_MASKED_LOAD]], <8 x double> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[TMP26:%.*]] = getelementptr double, ptr [[TMP20]], i32 -8
 ; AVX512-NEXT:    [[TMP27:%.*]] = getelementptr double, ptr [[TMP26]], i32 -7
-; AVX512-NEXT:    [[REVERSE14:%.*]] = shufflevector <8 x i1> [[TMP17]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[WIDE_MASKED_LOAD15:%.*]] = call <8 x double> @llvm.masked.load.v8f64.p0(ptr [[TMP27]], i32 8, <8 x i1> [[REVERSE14]], <8 x double> poison), !alias.scope !34
 ; AVX512-NEXT:    [[REVERSE16:%.*]] = shufflevector <8 x double> [[WIDE_MASKED_LOAD15]], <8 x double> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[TMP28:%.*]] = getelementptr double, ptr [[TMP20]], i32 -16
 ; AVX512-NEXT:    [[TMP29:%.*]] = getelementptr double, ptr [[TMP28]], i32 -7
-; AVX512-NEXT:    [[REVERSE17:%.*]] = shufflevector <8 x i1> [[TMP18]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[WIDE_MASKED_LOAD18:%.*]] = call <8 x double> @llvm.masked.load.v8f64.p0(ptr [[TMP29]], i32 8, <8 x i1> [[REVERSE17]], <8 x double> poison), !alias.scope !34
 ; AVX512-NEXT:    [[REVERSE19:%.*]] = shufflevector <8 x double> [[WIDE_MASKED_LOAD18]], <8 x double> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[TMP30:%.*]] = getelementptr double, ptr [[TMP20]], i32 -24
 ; AVX512-NEXT:    [[TMP31:%.*]] = getelementptr double, ptr [[TMP30]], i32 -7
-; AVX512-NEXT:    [[REVERSE20:%.*]] = shufflevector <8 x i1> [[TMP19]], <8 x i1> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[WIDE_MASKED_LOAD21:%.*]] = call <8 x double> @llvm.masked.load.v8f64.p0(ptr [[TMP31]], i32 8, <8 x i1> [[REVERSE20]], <8 x double> poison), !alias.scope !34
 ; AVX512-NEXT:    [[REVERSE22:%.*]] = shufflevector <8 x double> [[WIDE_MASKED_LOAD21]], <8 x double> poison, <8 x i32> <i32 7, i32 6, i32 5, i32 4, i32 3, i32 2, i32 1, i32 0>
 ; AVX512-NEXT:    [[TMP32:%.*]] = fadd <8 x double> [[REVERSE13]], <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>