1 ; RUN: opt < %s -instcombine -S | FileCheck %s 2 ; 3 ; This test makes sure that InstCombine does not replace the sequence of 4 ; xor/sub instruction followed by cmp instruction into a single cmp instruction 5 ; if there is more than one use of xor/sub. 6 7 define zeroext i1 @test1(i32 %lhs, i32 %rhs) { 8 ; CHECK-LABEL: @test1( 9 ; CHECK-NEXT: %xor = xor i32 %lhs, 5 10 ; CHECK-NEXT: %cmp1 = icmp eq i32 %xor, 10 11 12 %xor = xor i32 %lhs, 5 13 %cmp1 = icmp eq i32 %xor, 10 14 %cmp2 = icmp eq i32 %xor, %rhs 15 %sel = or i1 %cmp1, %cmp2 16 ret i1 %sel 17 } 18 19 define zeroext i1 @test2(i32 %lhs, i32 %rhs) { 20 ; CHECK-LABEL: @test2( 21 ; CHECK-NEXT: %xor = xor i32 %lhs, %rhs 22 ; CHECK-NEXT: %cmp1 = icmp eq i32 %xor, 0 23 24 %xor = xor i32 %lhs, %rhs 25 %cmp1 = icmp eq i32 %xor, 0 26 %cmp2 = icmp eq i32 %xor, 32 27 %sel = xor i1 %cmp1, %cmp2 28 ret i1 %sel 29 } 30 31 define zeroext i1 @test3(i32 %lhs, i32 %rhs) { 32 ; CHECK-LABEL: @test3( 33 ; CHECK-NEXT: %sub = sub nsw i32 %lhs, %rhs 34 ; CHECK-NEXT: %cmp1 = icmp eq i32 %sub, 0 35 36 %sub = sub nsw i32 %lhs, %rhs 37 %cmp1 = icmp eq i32 %sub, 0 38 %cmp2 = icmp eq i32 %sub, 31 39 %sel = or i1 %cmp1, %cmp2 40 ret i1 %sel 41 } 42
