; RUN: opt < %s -instcombine -S | FileCheck %s ; CHECK-LABEL: test1 ; CHECK: ret i1 true define i1 @test1(i8 %A) { %B = sitofp i8 %A to double %C = fcmp ult double %B, 128.0 ret i1 %C } ; CHECK-LABEL: test2 ; CHECK: ret i1 true define i1 @test2(i8 %A) { %B = sitofp i8 %A to double %C = fcmp ugt double %B, -128.1 ret i1 %C } ; CHECK-LABEL: test3 ; CHECK: ret i1 true define i1 @test3(i8 %A) { %B = sitofp i8 %A to double %C = fcmp ule double %B, 127.0 ret i1 %C } ; CHECK-LABEL: test4 ; CHECK: icmp ne i8 %A, 127 ; CHECK-NEXT: ret i1 define i1 @test4(i8 %A) { %B = sitofp i8 %A to double %C = fcmp ult double %B, 127.0 ret i1 %C } ; CHECK-LABEL: test5 ; CHECK: ret i32 define i32 @test5(i32 %A) { %B = sitofp i32 %A to double %C = fptosi double %B to i32 %D = uitofp i32 %C to double %E = fptoui double %D to i32 ret i32 %E } ; CHECK-LABEL: test6 ; CHECK: and i32 %A, 39 ; CHECK-NEXT: ret i32 define i32 @test6(i32 %A) { %B = and i32 %A, 7 %C = and i32 %A, 32 %D = sitofp i32 %B to double %E = sitofp i32 %C to double %F = fadd double %D, %E %G = fptosi double %F to i32 ret i32 %G } ; CHECK-LABEL: test7 ; CHECK: ret i32 define i32 @test7(i32 %A) nounwind { %B = sitofp i32 %A to double %C = fptoui double %B to i32 ret i32 %C } ; CHECK-LABEL: test8 ; CHECK: ret i32 define i32 @test8(i32 %A) nounwind { %B = uitofp i32 %A to double %C = fptosi double %B to i32 ret i32 %C } ; CHECK-LABEL: test9 ; CHECK: zext i8 ; CHECK-NEXT: ret i32 define i32 @test9(i8 %A) nounwind { %B = sitofp i8 %A to float %C = fptoui float %B to i32 ret i32 %C } ; CHECK-LABEL: test10 ; CHECK: sext i8 ; CHECK-NEXT: ret i32 define i32 @test10(i8 %A) nounwind { %B = sitofp i8 %A to float %C = fptosi float %B to i32 ret i32 %C } ; If the input value is outside of the range of the output cast, it's ; undefined behavior, so we can assume it fits. ; CHECK-LABEL: test11 ; CHECK: trunc ; CHECK-NEXT: ret i8 define i8 @test11(i32 %A) nounwind { %B = sitofp i32 %A to float %C = fptosi float %B to i8 ret i8 %C } ; If the input value is negative, it'll be outside the range of the ; output cast, and thus undefined behavior. ; CHECK-LABEL: test12 ; CHECK: zext i8 ; CHECK-NEXT: ret i32 define i32 @test12(i8 %A) nounwind { %B = sitofp i8 %A to float %C = fptoui float %B to i32 ret i32 %C } ; This can't fold because the 25-bit input doesn't fit in the mantissa. ; CHECK-LABEL: test13 ; CHECK: uitofp ; CHECK-NEXT: fptoui define i32 @test13(i25 %A) nounwind { %B = uitofp i25 %A to float %C = fptoui float %B to i32 ret i32 %C } ; But this one can. ; CHECK-LABEL: test14 ; CHECK: zext i24 ; CHECK-NEXT: ret i32 define i32 @test14(i24 %A) nounwind { %B = uitofp i24 %A to float %C = fptoui float %B to i32 ret i32 %C } ; And this one can too. ; CHECK-LABEL: test15 ; CHECK: trunc i32 ; CHECK-NEXT: ret i24 define i24 @test15(i32 %A) nounwind { %B = uitofp i32 %A to float %C = fptoui float %B to i24 ret i24 %C } ; This can fold because the 25-bit input is signed and we disard the sign bit. ; CHECK-LABEL: test16 ; CHECK: zext define i32 @test16(i25 %A) nounwind { %B = sitofp i25 %A to float %C = fptoui float %B to i32 ret i32 %C } ; This can't fold because the 26-bit input won't fit the mantissa ; even after disarding the signed bit. ; CHECK-LABEL: test17 ; CHECK: sitofp ; CHECK-NEXT: fptoui define i32 @test17(i26 %A) nounwind { %B = sitofp i26 %A to float %C = fptoui float %B to i32 ret i32 %C } ; This can fold because the 54-bit output is signed and we disard the sign bit. ; CHECK-LABEL: test18 ; CHECK: trunc define i54 @test18(i64 %A) nounwind { %B = sitofp i64 %A to double %C = fptosi double %B to i54 ret i54 %C } ; This can't fold because the 55-bit output won't fit the mantissa ; even after disarding the sign bit. ; CHECK-LABEL: test19 ; CHECK: sitofp ; CHECK-NEXT: fptosi define i55 @test19(i64 %A) nounwind { %B = sitofp i64 %A to double %C = fptosi double %B to i55 ret i55 %C }