[llvm] 7618355 - [InstCombine] add tests for smear-a-set-bit; NFC

[Sanjay Patel via llvm-commits]

Author: Sanjay Patel
Date: 2021-09-07T11:42:33-04:00
New Revision: 761835521cdb0fe42bb3d550e7fd65aede1ac56a

URL: https://github.com/llvm/llvm-project/commit/761835521cdb0fe42bb3d550e7fd65aede1ac56a
DIFF: https://github.com/llvm/llvm-project/commit/761835521cdb0fe42bb3d550e7fd65aede1ac56a.diff

LOG: [InstCombine] add tests for smear-a-set-bit; NFC

Possible follow-ups from patterns discussed in D109155.

Added: 
    

Modified: 
    llvm/test/Transforms/InstCombine/sext.ll

Removed: 
    


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diff  --git a/llvm/test/Transforms/InstCombine/sext.ll b/llvm/test/Transforms/InstCombine/sext.ll
index 1fc645cc9289..eec2f9be2f79 100644
--- a/llvm/test/Transforms/InstCombine/sext.ll
+++ b/llvm/test/Transforms/InstCombine/sext.ll
@@ -6,6 +6,8 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 declare i32 @llvm.ctpop.i32(i32)
 declare i32 @llvm.ctlz.i32(i32, i1)
 declare i32 @llvm.cttz.i32(i32, i1)
+declare void @use(i8)
+declare void @use_vec(<2 x i5>)
 
 define i64 @test1(i32 %x) {
 ; CHECK-LABEL: @test1(
@@ -318,3 +320,72 @@ define i10 @test19(i10 %i) {
   %d = sext i3 %c to i10
   ret i10 %d
 }
+
+define i32 @smear_set_bit(i32 %x) {
+; CHECK-LABEL: @smear_set_bit(
+; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[A:%.*]] = ashr i8 [[T]], 7
+; CHECK-NEXT:    [[S:%.*]] = sext i8 [[A]] to i32
+; CHECK-NEXT:    ret i32 [[S]]
+;
+  %t = trunc i32 %x to i8
+  %a = ashr i8 %t, 7
+  %s = sext i8 %a to i32
+  ret i32 %s
+}
+
+define <2 x i32> @smear_set_bit_vec_use1(<2 x i32> %x) {
+; CHECK-LABEL: @smear_set_bit_vec_use1(
+; CHECK-NEXT:    [[T:%.*]] = trunc <2 x i32> [[X:%.*]] to <2 x i5>
+; CHECK-NEXT:    call void @use_vec(<2 x i5> [[T]])
+; CHECK-NEXT:    [[A:%.*]] = ashr <2 x i5> [[T]], <i5 4, i5 4>
+; CHECK-NEXT:    [[S:%.*]] = sext <2 x i5> [[A]] to <2 x i32>
+; CHECK-NEXT:    ret <2 x i32> [[S]]
+;
+  %t = trunc <2 x i32> %x to <2 x i5>
+  call void @use_vec(<2 x i5> %t)
+  %a = ashr <2 x i5> %t, <i5 4, i5 4>
+  %s = sext <2 x i5> %a to <2 x i32>
+  ret <2 x i32> %s
+}
+
+define i32 @smear_set_bit_use2(i32 %x) {
+; CHECK-LABEL: @smear_set_bit_use2(
+; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[A:%.*]] = ashr i8 [[T]], 7
+; CHECK-NEXT:    call void @use(i8 [[A]])
+; CHECK-NEXT:    [[S:%.*]] = sext i8 [[A]] to i32
+; CHECK-NEXT:    ret i32 [[S]]
+;
+  %t = trunc i32 %x to i8
+  %a = ashr i8 %t, 7
+  call void @use(i8 %a)
+  %s = sext i8 %a to i32
+  ret i32 %s
+}
+
+define i32 @smear_set_bit_wrong_shift_amount(i32 %x) {
+; CHECK-LABEL: @smear_set_bit_wrong_shift_amount(
+; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[A:%.*]] = ashr i8 [[T]], 6
+; CHECK-NEXT:    [[S:%.*]] = sext i8 [[A]] to i32
+; CHECK-NEXT:    ret i32 [[S]]
+;
+  %t = trunc i32 %x to i8
+  %a = ashr i8 %t, 6
+  %s = sext i8 %a to i32
+  ret i32 %s
+}
+
+define i16 @smear_set_bit_
diff erent_dest_type(i32 %x) {
+; CHECK-LABEL: @smear_set_bit_
diff erent_dest_type(
+; CHECK-NEXT:    [[T:%.*]] = trunc i32 [[X:%.*]] to i8
+; CHECK-NEXT:    [[A:%.*]] = ashr i8 [[T]], 7
+; CHECK-NEXT:    [[S:%.*]] = sext i8 [[A]] to i16
+; CHECK-NEXT:    ret i16 [[S]]
+;
+  %t = trunc i32 %x to i8
+  %a = ashr i8 %t, 7
+  %s = sext i8 %a to i16
+  ret i16 %s
+}