1; RUN: opt < %s -reassociate -instcombine -S | FileCheck %s 2 3; With sub reassociation, constant folding can eliminate the 12 and -12 constants. 4define i32 @test1(i32 %A, i32 %B) { 5; CHECK-LABEL: @test1 6; CHECK-NEXT: %Z = sub i32 %A, %B 7; CHECK-NEXT: ret i32 %Z 8 %X = add i32 -12, %A 9 %Y = sub i32 %X, %B 10 %Z = add i32 %Y, 12 11 ret i32 %Z 12} 13 14; PR2047 15; With sub reassociation, constant folding can eliminate the uses of %a. 16define i32 @test2(i32 %a, i32 %b, i32 %c) nounwind { 17; CHECK-LABEL: @test2 18; CHECK-NEXT: %sum = add i32 %c, %b 19; CHECK-NEXT: %tmp7 = sub i32 0, %sum 20; CHECK-NEXT: ret i32 %tmp7 21 22 %tmp3 = sub i32 %a, %b 23 %tmp5 = sub i32 %tmp3, %c 24 %tmp7 = sub i32 %tmp5, %a 25 ret i32 %tmp7 26} 27