[llvm] 762629b - [InstCombine] Add additional tests for nsw propagation during negation (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-08-23T11:38:41+02:00
New Revision: 762629b2c67a7dc3961b868528c3770a4fa8b068

URL: https://github.com/llvm/llvm-project/commit/762629b2c67a7dc3961b868528c3770a4fa8b068
DIFF: https://github.com/llvm/llvm-project/commit/762629b2c67a7dc3961b868528c3770a4fa8b068.diff

LOG: [InstCombine] Add additional tests for nsw propagation during negation (NFC)

Added: 
    

Modified: 
    llvm/test/Transforms/InstCombine/mul.ll
    llvm/test/Transforms/InstCombine/nsw.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/InstCombine/mul.ll b/llvm/test/Transforms/InstCombine/mul.ll
index de2b5115266360..7e41b073d738f6 100644
--- a/llvm/test/Transforms/InstCombine/mul.ll
+++ b/llvm/test/Transforms/InstCombine/mul.ll
@@ -1543,6 +1543,28 @@ define <2 x i32> @mulsub2_vec_nonuniform_undef(<2 x i32> %a0) {
   ret <2 x i32> %mul
 }
 
+define i8 @mulsub_nsw(i8 %a1, i8 %a2) {
+; CHECK-LABEL: @mulsub_nsw(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[MUL:%.*]] = shl i8 [[A_NEG]], 1
+; CHECK-NEXT:    ret i8 [[MUL]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %mul = mul nsw i8 %a, -2
+  ret i8 %mul
+}
+
+define <2 x i8> @mulsub_nsw_undef(<2 x i8> %a1, <2 x i8> %a2) {
+; CHECK-LABEL: @mulsub_nsw_undef(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub <2 x i8> [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[MUL:%.*]] = shl <2 x i8> [[A_NEG]], <i8 1, i8 0>
+; CHECK-NEXT:    ret <2 x i8> [[MUL]]
+;
+  %a = sub nsw <2 x i8> %a1, %a2
+  %mul = mul nsw <2 x i8> %a, <i8 -2, i8 undef>
+  ret <2 x i8> %mul
+}
+
 define i32 @muladd2(i32 %a0) {
 ; CHECK-LABEL: @muladd2(
 ; CHECK-NEXT:    [[TMP1:%.*]] = shl i32 [[A0:%.*]], 2

diff  --git a/llvm/test/Transforms/InstCombine/nsw.ll b/llvm/test/Transforms/InstCombine/nsw.ll
index ea66409b34267a..d9dfa8fb387683 100644
--- a/llvm/test/Transforms/InstCombine/nsw.ll
+++ b/llvm/test/Transforms/InstCombine/nsw.ll
@@ -253,6 +253,47 @@ define i32 @sub_sub1_nsw_nsw(i32 %a, i32 %b, i32 %c) {
   ret i32 %s2
 }
 
+define i8 @neg_nsw_freeze(i8 %a1, i8 %a2) {
+; CHECK-LABEL: @neg_nsw_freeze(
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    [[FR_NEG:%.*]] = freeze i8 [[A_NEG]]
+; CHECK-NEXT:    ret i8 [[FR_NEG]]
+;
+  %a = sub nsw i8 %a1, %a2
+  %fr = freeze i8 %a
+  %neg = sub nsw i8 0, %fr
+  ret i8 %neg
+}
+
+define i8 @neg_nsw_phi(i1 %c, i8 %a1, i8 %a2, i8 %b1, i8 %b2) {
+; CHECK-LABEL: @neg_nsw_phi(
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]
+; CHECK-NEXT:    br label [[JOIN:%.*]]
+; CHECK:       else:
+; CHECK-NEXT:    [[B_NEG:%.*]] = sub i8 [[B2:%.*]], [[B1:%.*]]
+; CHECK-NEXT:    br label [[JOIN]]
+; CHECK:       join:
+; CHECK-NEXT:    [[PHI_NEG:%.*]] = phi i8 [ [[A_NEG]], [[IF]] ], [ [[B_NEG]], [[ELSE]] ]
+; CHECK-NEXT:    ret i8 [[PHI_NEG]]
+;
+  br i1 %c, label %if, label %else
+
+if:
+  %a = sub nsw i8 %a1, %a2
+  br label %join
+
+else:
+  %b = sub nsw i8 %b1, %b2
+  br label %join
+
+join:
+  %phi = phi i8 [ %a, %if ], [ %b, %else ]
+  %neg = sub nsw i8 0, %phi
+  ret i8 %neg
+}
+
 define i8 @neg_nsw_select(i1 %c, i8 %a1, i8 %a2, i8 %b1, i8 %b2) {
 ; CHECK-LABEL: @neg_nsw_select(
 ; CHECK-NEXT:    [[A_NEG:%.*]] = sub i8 [[A2:%.*]], [[A1:%.*]]