| ; RUN: llc -mtriple=x86_64-apple-macosx -O3 -debug-only=faultmaps -enable-implicit-null-checks < %s | FileCheck %s |
| ; REQUIRES: asserts |
| |
| ; List cases where we should *not* be emitting implicit null checks. |
| |
| ; CHECK-NOT: Fault Map Output |
| |
| define i32 @imp_null_check_load(i32* %x, i32* %y) { |
| entry: |
| %c = icmp eq i32* %x, null |
| ; It isn't legal to move the load from %x from "not_null" to here -- |
| ; the store to %y could be aliasing it. |
| br i1 %c, label %is_null, label %not_null |
| |
| is_null: |
| ret i32 42 |
| |
| not_null: |
| store i32 0, i32* %y |
| %t = load i32, i32* %x |
| ret i32 %t |
| } |
| |
| define i32 @imp_null_check_gep_load(i32* %x) { |
| entry: |
| %c = icmp eq i32* %x, null |
| br i1 %c, label %is_null, label %not_null |
| |
| is_null: |
| ret i32 42 |
| |
| not_null: |
| ; null + 5000 * sizeof(i32) lies outside the null page and hence the |
| ; load to %t cannot be assumed to be reliably faulting. |
| %x.gep = getelementptr i32, i32* %x, i32 5000 |
| %t = load i32, i32* %x.gep |
| ret i32 %t |
| } |
| |
| define i32 @imp_null_check_load_no_md(i32* %x) { |
| ; Everything is okay except that the !never.executed metadata is |
| ; missing. |
| entry: |
| %c = icmp eq i32* %x, null |
| br i1 %c, label %is_null, label %not_null |
| |
| is_null: |
| ret i32 42 |
| |
| not_null: |
| %t = load i32, i32* %x |
| ret i32 %t |
| } |