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; RUN: opt < %s -instcombine -S | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
; CHECK-LABEL: @oppositesign
; CHECK: add nsw i16 %a, %b
define i16 @oppositesign(i16 %x, i16 %y) {
; %a is negative, %b is positive
%a = or i16 %x, 32768
%b = and i16 %y, 32767
%c = add i16 %a, %b
ret i16 %c
}
define i16 @zero_sign_bit(i16 %a) {
; CHECK-LABEL: @zero_sign_bit(
; CHECK-NEXT: and
; CHECK-NEXT: add nuw
; CHECK-NEXT: ret
%1 = and i16 %a, 32767
%2 = add i16 %1, 512
ret i16 %2
}
define i16 @zero_sign_bit2(i16 %a, i16 %b) {
; CHECK-LABEL: @zero_sign_bit2(
; CHECK-NEXT: and
; CHECK-NEXT: and
; CHECK-NEXT: add nuw
; CHECK-NEXT: ret
%1 = and i16 %a, 32767
%2 = and i16 %b, 32767
%3 = add i16 %1, %2
ret i16 %3
}
; CHECK-LABEL: @ripple_nsw1
; CHECK: add nsw i16 %a, %b
define i16 @ripple_nsw1(i16 %x, i16 %y) {
; %a has at most one bit set
%a = and i16 %y, 1
; %b has a 0 bit other than the sign bit
%b = and i16 %x, 49151
%c = add i16 %a, %b
ret i16 %c
}
; Like the previous test, but flip %a and %b
; CHECK-LABEL: @ripple_nsw2
; CHECK: add nsw i16 %b, %a
define i16 @ripple_nsw2(i16 %x, i16 %y) {
%a = and i16 %y, 1
%b = and i16 %x, 49151
%c = add i16 %b, %a
ret i16 %c
}
; CHECK-LABEL: @ripple_no_nsw1
; CHECK: add i32 %a, %x
define i32 @ripple_no_nsw1(i32 %x, i32 %y) {
; We know nothing about %x
%a = and i32 %y, 1
%b = add i32 %a, %x
ret i32 %b
}
; CHECK-LABEL: @ripple_no_nsw2
; CHECK: add nuw i16 %a, %b
define i16 @ripple_no_nsw2(i16 %x, i16 %y) {
; %a has at most one bit set
%a = and i16 %y, 1
; %b has a 0 bit, but it is the sign bit
%b = and i16 %x, 32767
%c = add i16 %a, %b
ret i16 %c
}
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