54 lines
1 KiB
Rust
54 lines
1 KiB
Rust
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// compile-flags: -O
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// only-x86_64
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#![crate_type = "rlib"]
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#![feature(asm)]
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// CHECK-LABEL: @pure
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// CHECK-NOT: asm
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// CHECK: ret void
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#[no_mangle]
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pub unsafe fn pure(x: i32) {
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let y: i32;
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asm!("", out("ax") y, in("bx") x, options(pure), options(nomem));
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}
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pub static mut VAR: i32 = 0;
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pub static mut DUMMY_OUTPUT: i32 = 0;
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// CHECK-LABEL: @readonly
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// CHECK: call i32 asm
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// CHECK: ret i32 1
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#[no_mangle]
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pub unsafe fn readonly() -> i32 {
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VAR = 1;
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asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
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VAR
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}
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// CHECK-LABEL: @nomem
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// CHECK-NOT: store
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// CHECK: call i32 asm
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// CHECK: store
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// CHECK: ret i32 2
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#[no_mangle]
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pub unsafe fn nomem() -> i32 {
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VAR = 1;
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asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(nomem));
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VAR = 2;
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VAR
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}
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// CHECK-LABEL: @not_nomem
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// CHECK: store
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// CHECK: call i32 asm
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// CHECK: store
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// CHECK: ret i32 2
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#[no_mangle]
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pub unsafe fn not_nomem() -> i32 {
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VAR = 1;
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asm!("", out("ax") DUMMY_OUTPUT, options(pure), options(readonly));
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VAR = 2;
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VAR
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}
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