[llvm] r358031 - [InstCombine] Add with.overflow always overflow tests; NFC

[Nikita Popov via llvm-commits]

Author: nikic
Date: Tue Apr  9 13:02:23 2019
New Revision: 358031

URL: http://llvm.org/viewvc/llvm-project?rev=358031&view=rev
Log:
[InstCombine] Add with.overflow always overflow tests; NFC

The uadd and umul cases are currently handled, the usub, sadd, ssub
and smul cases are not. usub, sadd and ssub already have the
necessary ValueTracking support, smul doesn't.

Modified:
    llvm/trunk/test/Transforms/InstCombine/with_overflow.ll

Modified: llvm/trunk/test/Transforms/InstCombine/with_overflow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/with_overflow.ll?rev=358031&r1=358030&r2=358031&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/with_overflow.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/with_overflow.ll Tue Apr  9 13:02:23 2019
@@ -2,7 +2,11 @@
 ; RUN: opt -instcombine -S < %s | FileCheck %s
 
 declare { i8, i1 } @llvm.uadd.with.overflow.i8(i8, i8) nounwind readnone
+declare { i8, i1 } @llvm.sadd.with.overflow.i8(i8, i8) nounwind readnone
+declare { i8, i1 } @llvm.usub.with.overflow.i8(i8, i8) nounwind readnone
+declare { i8, i1 } @llvm.ssub.with.overflow.i8(i8, i8) nounwind readnone
 declare { i8, i1 } @llvm.umul.with.overflow.i8(i8, i8) nounwind readnone
+declare { i8, i1 } @llvm.smul.with.overflow.i8(i8, i8) nounwind readnone
 declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) nounwind readnone
 declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) nounwind readnone
 declare { i32, i1 } @llvm.ssub.with.overflow.i32(i32, i32) nounwind readnone
@@ -522,3 +526,78 @@ define { i32, i1 } @umul_canonicalize_co
   %a = call { i32, i1 } @llvm.umul.with.overflow.i32(i32 42, i32 %x)
   ret { i32, i1 } %a
 }
+
+; Always overflow tests
+
+define { i8, i1 } @uadd_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @uadd_always_overflow(
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[X:%.*]], -64
+; CHECK-NEXT:    [[A:%.*]] = add nsw i8 [[Y]], 64
+; CHECK-NEXT:    [[TMP1:%.*]] = insertvalue { i8, i1 } { i8 undef, i1 true }, i8 [[A]], 0
+; CHECK-NEXT:    ret { i8, i1 } [[TMP1]]
+;
+  %y = or i8 %x, 192
+  %a = call { i8, i1 } @llvm.uadd.with.overflow.i8(i8 %y, i8 64)
+  ret { i8, i1 } %a
+}
+
+define { i8, i1 } @usub_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @usub_always_overflow(
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[X:%.*]], 64
+; CHECK-NEXT:    [[A:%.*]] = call { i8, i1 } @llvm.usub.with.overflow.i8(i8 63, i8 [[Y]])
+; CHECK-NEXT:    ret { i8, i1 } [[A]]
+;
+  %y = or i8 %x, 64
+  %a = call { i8, i1 } @llvm.usub.with.overflow.i8(i8 63, i8 %y)
+  ret { i8, i1 } %a
+}
+
+define { i8, i1 } @umul_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @umul_always_overflow(
+; CHECK-NEXT:    [[A:%.*]] = shl i8 [[X:%.*]], 1
+; CHECK-NEXT:    [[TMP1:%.*]] = insertvalue { i8, i1 } { i8 undef, i1 true }, i8 [[A]], 0
+; CHECK-NEXT:    ret { i8, i1 } [[TMP1]]
+;
+  %y = or i8 %x, 128
+  %a = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 %y, i8 2)
+  ret { i8, i1 } %a
+}
+
+define { i8, i1 } @sadd_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @sadd_always_overflow(
+; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[X:%.*]], 100
+; CHECK-NEXT:    [[Y:%.*]] = select i1 [[C]], i8 [[X]], i8 100
+; CHECK-NEXT:    [[A:%.*]] = call { i8, i1 } @llvm.sadd.with.overflow.i8(i8 [[Y]], i8 28)
+; CHECK-NEXT:    ret { i8, i1 } [[A]]
+;
+  %c = icmp sgt i8 %x, 100
+  %y = select i1 %c, i8 %x, i8 100
+  %a = call { i8, i1 } @llvm.sadd.with.overflow.i8(i8 %y, i8 28)
+  ret { i8, i1 } %a
+}
+
+define { i8, i1 } @ssub_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @ssub_always_overflow(
+; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[X:%.*]], 29
+; CHECK-NEXT:    [[Y:%.*]] = select i1 [[C]], i8 [[X]], i8 29
+; CHECK-NEXT:    [[A:%.*]] = call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 -100, i8 [[Y]])
+; CHECK-NEXT:    ret { i8, i1 } [[A]]
+;
+  %c = icmp sgt i8 %x, 29
+  %y = select i1 %c, i8 %x, i8 29
+  %a = call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 -100, i8 %y)
+  ret { i8, i1 } %a
+}
+
+define { i8, i1 } @smul_always_overflow(i8 %x) nounwind {
+; CHECK-LABEL: @smul_always_overflow(
+; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[X:%.*]], 100
+; CHECK-NEXT:    [[Y:%.*]] = select i1 [[C]], i8 [[X]], i8 100
+; CHECK-NEXT:    [[A:%.*]] = call { i8, i1 } @llvm.smul.with.overflow.i8(i8 [[Y]], i8 2)
+; CHECK-NEXT:    ret { i8, i1 } [[A]]
+;
+  %c = icmp sgt i8 %x, 100
+  %y = select i1 %c, i8 %x, i8 100
+  %a = call { i8, i1 } @llvm.smul.with.overflow.i8(i8 %y, i8 2)
+  ret { i8, i1 } %a
+}