| ; RUN: llc -O2 < %s | FileCheck %s --check-prefix=CHECK-O2 --check-prefix=CHECK |
| ; RUN: llc -O0 -fast-isel < %s | FileCheck %s --check-prefix=CHECK-O0 --check-prefix=CHECK |
| ; RUN: llc -O0 -fast-isel=0 < %s | FileCheck %s --check-prefix=CHECK-O0 --check-prefix=CHECK |
| ; RUN: llc -O0 -global-isel < %s | FileCheck %s --check-prefix=CHECK-O0 --check-prefix=CHECK |
| |
| ;; Ensure that an unfoldable is.constant gets lowered reasonably in |
| ;; optimized codegen, in particular, that the "true" branch is |
| ;; eliminated. |
| ;; |
| ;; This isn't asserting any specific output from non-optimized runs, |
| ;; (e.g., currently the not-taken branch does not get eliminated). But |
| ;; it does ensure that lowering succeeds in all 3 codegen paths. |
| |
| target triple = "x86_64-unknown-linux-gnu" |
| |
| declare i1 @llvm.is.constant.i32(i32 %a) nounwind readnone |
| declare i1 @llvm.is.constant.i64(i64 %a) nounwind readnone |
| declare i64 @llvm.objectsize.i64.p0i8(i8*, i1, i1, i1) nounwind readnone |
| |
| declare i32 @subfun_1() |
| declare i32 @subfun_2() |
| |
| define i32 @test_branch(i32 %in) nounwind { |
| ; CHECK-LABEL: test_branch: |
| ; CHECK-O2: %bb.0: |
| ; CHECK-O2-NEXT: jmp subfun_2 |
| %v = call i1 @llvm.is.constant.i32(i32 %in) |
| br i1 %v, label %True, label %False |
| |
| True: |
| %call1 = tail call i32 @subfun_1() |
| ret i32 %call1 |
| |
| False: |
| %call2 = tail call i32 @subfun_2() |
| ret i32 %call2 |
| } |
| |
| ;; llvm.objectsize is another tricky case which gets folded to -1 very |
| ;; late in the game. We'd like to ensure that llvm.is.constant of |
| ;; llvm.objectsize is true. |
| define i1 @test_objectsize(i8* %obj) nounwind { |
| ; CHECK-LABEL: test_objectsize: |
| ; CHECK-O2: %bb.0: |
| ; CHECK-O2: movb $1, %al |
| ; CHECK-O2-NEXT: retq |
| %os = call i64 @llvm.objectsize.i64.p0i8(i8* %obj, i1 false, i1 false, i1 false) |
| %v = call i1 @llvm.is.constant.i64(i64 %os) |
| ret i1 %v |
| } |