[LV] Don't emit unused scalars for uniform instructions

If we identify an instruction as uniform after vectorization, we know that we
should only use the value corresponding to the first vector lane of each unroll
iteration. However, when scalarizing such instructions, we still produce values
for the other vector lanes. This patch prevents us from generating the unused
scalars.

Differential Revision: https://reviews.llvm.org/D24275

llvm-svn: 282087

2 files changed, 0 insertions, 38 deletions

diff --git a/llvm/test/Transforms/LoopVectorize/induction.ll b/llvm/test/Transforms/LoopVectorize/induction.ll
index 8adb6a35383..1866263c3b5 100644
--- a/llvm/test/Transforms/LoopVectorize/induction.ll
+++ b/llvm/test/Transforms/LoopVectorize/induction.ll
@@ -78,21 +78,15 @@ loopexit:
 ; CHECK: vector.body:
 ; CHECK:   %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK:   %[[i0:.+]] = add i64 %index, 0
-; CHECK:   %[[i1:.+]] = add i64 %index, 1
 ; CHECK:   getelementptr inbounds i64, i64* %a, i64 %[[i0]]
-; CHECK:   getelementptr inbounds i64, i64* %a, i64 %[[i1]]
 ;
 ; UNROLL-NO-IC-LABEL: @scalarize_induction_variable_01(
 ; UNROLL-NO-IC: vector.body:
 ; UNROLL-NO-IC:   %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; UNROLL-NO-IC:   %[[i0:.+]] = add i64 %index, 0
-; UNROLL-NO-IC:   %[[i1:.+]] = add i64 %index, 1
 ; UNROLL-NO-IC:   %[[i2:.+]] = add i64 %index, 2
-; UNROLL-NO-IC:   %[[i3:.+]] = add i64 %index, 3
 ; UNROLL-NO-IC:   getelementptr inbounds i64, i64* %a, i64 %[[i0]]
-; UNROLL-NO-IC:   getelementptr inbounds i64, i64* %a, i64 %[[i1]]
 ; UNROLL-NO-IC:   getelementptr inbounds i64, i64* %a, i64 %[[i2]]
-; UNROLL-NO-IC:   getelementptr inbounds i64, i64* %a, i64 %[[i3]]
 ;
 ; IND-LABEL: @scalarize_induction_variable_01(
 ; IND:     vector.body:
@@ -611,9 +605,7 @@ exit:
 ; CHECK:   %vec.ind = phi <2 x i32> [ %[[START]], %vector.ph ], [ %vec.ind.next, %vector.body ]
 ; CHECK:   %offset.idx = add i32 %i, %index
 ; CHECK:   %[[A1:.*]] = add i32 %offset.idx, 0
-; CHECK:   %[[A2:.*]] = add i32 %offset.idx, 1
 ; CHECK:   %[[G1:.*]] = getelementptr inbounds i32, i32* %a, i32 %[[A1]]
-; CHECK:   %[[G2:.*]] = getelementptr inbounds i32, i32* %a, i32 %[[A2]]
 ; CHECK:   %[[G3:.*]] = getelementptr i32, i32* %[[G1]], i32 0
 ; CHECK:   %[[B1:.*]] = bitcast i32* %[[G3]] to <2 x i32>*
 ; CHECK:   store <2 x i32> %vec.ind, <2 x i32>* %[[B1]]
diff --git a/llvm/test/Transforms/LoopVectorize/reverse_induction.ll b/llvm/test/Transforms/LoopVectorize/reverse_induction.ll
index ae8f9b3390d..ce81e1f83fd 100644
--- a/llvm/test/Transforms/LoopVectorize/reverse_induction.ll
+++ b/llvm/test/Transforms/LoopVectorize/reverse_induction.ll
@@ -8,13 +8,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 ; CHECK: %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK: %offset.idx = sub i64 %startval, %index
 ; CHECK: %[[a0:.+]] = add i64 %offset.idx, 0
-; CHECK: %[[a1:.+]] = add i64 %offset.idx, -1
-; CHECK: %[[a2:.+]] = add i64 %offset.idx, -2
-; CHECK: %[[a3:.+]] = add i64 %offset.idx, -3
 ; CHECK: %[[a4:.+]] = add i64 %offset.idx, -4
-; CHECK: %[[a5:.+]] = add i64 %offset.idx, -5
-; CHECK: %[[a6:.+]] = add i64 %offset.idx, -6
-; CHECK: %[[a7:.+]] = add i64 %offset.idx, -7
 
 define i32 @reverse_induction_i64(i64 %startval, i32 * %ptr) {
 entry:
@@ -40,13 +34,7 @@ loopend:
 ; CHECK: %index = phi i128 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK: %offset.idx = sub i128 %startval, %index
 ; CHECK: %[[a0:.+]] = add i128 %offset.idx, 0
-; CHECK: %[[a1:.+]] = add i128 %offset.idx, -1
-; CHECK: %[[a2:.+]] = add i128 %offset.idx, -2
-; CHECK: %[[a3:.+]] = add i128 %offset.idx, -3
 ; CHECK: %[[a4:.+]] = add i128 %offset.idx, -4
-; CHECK: %[[a5:.+]] = add i128 %offset.idx, -5
-; CHECK: %[[a6:.+]] = add i128 %offset.idx, -6
-; CHECK: %[[a7:.+]] = add i128 %offset.idx, -7
 
 define i32 @reverse_induction_i128(i128 %startval, i32 * %ptr) {
 entry:
@@ -72,13 +60,7 @@ loopend:
 ; CHECK: %index = phi i32 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK: %offset.idx = sub i16 %startval, {{.*}}
 ; CHECK: %[[a0:.+]] = add i16 %offset.idx, 0
-; CHECK: %[[a1:.+]] = add i16 %offset.idx, -1
-; CHECK: %[[a2:.+]] = add i16 %offset.idx, -2
-; CHECK: %[[a3:.+]] = add i16 %offset.idx, -3
 ; CHECK: %[[a4:.+]] = add i16 %offset.idx, -4
-; CHECK: %[[a5:.+]] = add i16 %offset.idx, -5
-; CHECK: %[[a6:.+]] = add i16 %offset.idx, -6
-; CHECK: %[[a7:.+]] = add i16 %offset.idx, -7
 
 define i32 @reverse_induction_i16(i16 %startval, i32 * %ptr) {
 entry:
@@ -121,13 +103,7 @@ loopend:
 ; CHECK: %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK: %offset.idx = sub i64 1023, %index
 ; CHECK: %[[a0:.+]] = add i64 %offset.idx, 0
-; CHECK: %[[a1:.+]] = add i64 %offset.idx, -1
-; CHECK: %[[a2:.+]] = add i64 %offset.idx, -2
-; CHECK: %[[a3:.+]] = add i64 %offset.idx, -3
 ; CHECK: %[[a4:.+]] = add i64 %offset.idx, -4
-; CHECK: %[[a5:.+]] = add i64 %offset.idx, -5
-; CHECK: %[[a6:.+]] = add i64 %offset.idx, -6
-; CHECK: %[[a7:.+]] = add i64 %offset.idx, -7
 
 define void @reverse_forward_induction_i64_i8() {
 entry:
@@ -153,13 +129,7 @@ while.end:
 ; CHECK: %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
 ; CHECK: %offset.idx = sub i64 1023, %index
 ; CHECK: %[[a0:.+]] = add i64 %offset.idx, 0
-; CHECK: %[[a1:.+]] = add i64 %offset.idx, -1
-; CHECK: %[[a2:.+]] = add i64 %offset.idx, -2
-; CHECK: %[[a3:.+]] = add i64 %offset.idx, -3
 ; CHECK: %[[a4:.+]] = add i64 %offset.idx, -4
-; CHECK: %[[a5:.+]] = add i64 %offset.idx, -5
-; CHECK: %[[a6:.+]] = add i64 %offset.idx, -6
-; CHECK: %[[a7:.+]] = add i64 %offset.idx, -7
 
 define void @reverse_forward_induction_i64_i8_signed() {
 entry: