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committedMay 16, 2021
Auto merge of rust-lang#85290 - Amanieu:asm_const_int, r=nagisa
Remove support for floating-point constants in asm! Floating-point constants aren't very useful anyways and this simplifies the code since the type check can now be done in typeck. cc `@rust-lang/wg-inline-asm` r? `@nagisa`
2 parents f8e1e92 + 1605e0e commit 7dc9ff5

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8 files changed

+70
-91
lines changed

8 files changed

+70
-91
lines changed
 

‎compiler/rustc_codegen_ssa/src/common.rs

-2
Original file line numberDiff line numberDiff line change
@@ -219,8 +219,6 @@ pub fn asm_const_to_str<'tcx>(
219219
ty::IntTy::I128 => (value as i128).to_string(),
220220
ty::IntTy::Isize => unreachable!(),
221221
},
222-
ty::Float(ty::FloatTy::F32) => f32::from_bits(value as u32).to_string(),
223-
ty::Float(ty::FloatTy::F64) => f64::from_bits(value as u64).to_string(),
224222
_ => span_bug!(sp, "asm const has bad type {}", ty_and_layout.ty),
225223
}
226224
}

‎compiler/rustc_passes/src/intrinsicck.rs

+2-41
Original file line numberDiff line numberDiff line change
@@ -347,7 +347,7 @@ impl ExprVisitor<'tcx> {
347347
}
348348

349349
fn check_asm(&self, asm: &hir::InlineAsm<'tcx>) {
350-
for (idx, (op, op_sp)) in asm.operands.iter().enumerate() {
350+
for (idx, (op, _)) in asm.operands.iter().enumerate() {
351351
match *op {
352352
hir::InlineAsmOperand::In { reg, ref expr } => {
353353
self.check_asm_operand_type(idx, reg, expr, asm.template, None);
@@ -372,19 +372,7 @@ impl ExprVisitor<'tcx> {
372372
);
373373
}
374374
}
375-
hir::InlineAsmOperand::Const { ref anon_const } => {
376-
let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id);
377-
let value = ty::Const::from_anon_const(self.tcx, anon_const_def_id);
378-
match value.ty.kind() {
379-
ty::Int(_) | ty::Uint(_) | ty::Float(_) => {}
380-
_ => {
381-
let msg =
382-
"asm `const` arguments must be integer or floating-point values";
383-
self.tcx.sess.span_err(*op_sp, msg);
384-
}
385-
}
386-
}
387-
hir::InlineAsmOperand::Sym { .. } => {}
375+
hir::InlineAsmOperand::Const { .. } | hir::InlineAsmOperand::Sym { .. } => {}
388376
}
389377
}
390378
}
@@ -405,33 +393,6 @@ impl Visitor<'tcx> for ItemVisitor<'tcx> {
405393
ExprVisitor { tcx: self.tcx, param_env, typeck_results }.visit_body(body);
406394
self.visit_body(body);
407395
}
408-
409-
fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
410-
if let hir::ItemKind::GlobalAsm(asm) = item.kind {
411-
for (op, op_sp) in asm.operands {
412-
match *op {
413-
hir::InlineAsmOperand::Const { ref anon_const } => {
414-
let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id);
415-
let value = ty::Const::from_anon_const(self.tcx, anon_const_def_id);
416-
match value.ty.kind() {
417-
ty::Int(_) | ty::Uint(_) | ty::Float(_) => {}
418-
_ => {
419-
let msg = "asm `const` arguments must be integer or floating-point values";
420-
self.tcx.sess.span_err(*op_sp, msg);
421-
}
422-
}
423-
}
424-
hir::InlineAsmOperand::In { .. }
425-
| hir::InlineAsmOperand::Out { .. }
426-
| hir::InlineAsmOperand::InOut { .. }
427-
| hir::InlineAsmOperand::SplitInOut { .. }
428-
| hir::InlineAsmOperand::Sym { .. } => unreachable!(),
429-
}
430-
}
431-
}
432-
433-
intravisit::walk_item(self, item);
434-
}
435396
}
436397

437398
impl Visitor<'tcx> for ExprVisitor<'tcx> {

‎compiler/rustc_typeck/src/check/mod.rs

+2-4
Original file line numberDiff line numberDiff line change
@@ -554,10 +554,8 @@ fn typeck_with_fallback<'tcx>(
554554
_ => false,
555555
}) =>
556556
{
557-
fcx.next_ty_var(TypeVariableOrigin {
558-
kind: TypeVariableOriginKind::MiscVariable,
559-
span,
560-
})
557+
// Inline assembly constants must be integers.
558+
fcx.next_int_var()
561559
}
562560
_ => fallback(),
563561
},

‎src/doc/unstable-book/src/library-features/asm.md

+1-1
Original file line numberDiff line numberDiff line change
@@ -509,7 +509,7 @@ Several types of operands are supported:
509509
- Identical to `inout` except that the register allocator can reuse a register allocated to an `in` (this can happen if the compiler knows the `in` has the same initial value as the `inlateout`).
510510
- You should only write to the register after all inputs are read, otherwise you may clobber an input.
511511
* `const <expr>`
512-
- `<expr>` must be an integer or floating-point constant expression.
512+
- `<expr>` must be an integer constant expression.
513513
- The value of the expression is formatted as a string and substituted directly into the asm template string.
514514
* `sym <path>`
515515
- `<path>` must refer to a `fn` or `static`.

‎src/test/ui/asm/type-check-1.rs

+21-1
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// only-x86_64
22

3-
#![feature(asm)]
3+
#![feature(asm, global_asm)]
44

55
fn main() {
66
unsafe {
@@ -39,5 +39,25 @@ fn main() {
3939
asm!("{}", const const_bar(0));
4040
asm!("{}", const const_bar(x));
4141
//~^ ERROR attempt to use a non-constant value in a constant
42+
43+
// Const operands must be integers and must be constants.
44+
45+
asm!("{}", const 0);
46+
asm!("{}", const 0i32);
47+
asm!("{}", const 0i128);
48+
asm!("{}", const 0f32);
49+
//~^ ERROR mismatched types
50+
asm!("{}", const 0 as *mut u8);
51+
//~^ ERROR mismatched types
4252
}
4353
}
54+
55+
// Const operands must be integers and must be constants.
56+
57+
global_asm!("{}", const 0);
58+
global_asm!("{}", const 0i32);
59+
global_asm!("{}", const 0i128);
60+
global_asm!("{}", const 0f32);
61+
//~^ ERROR mismatched types
62+
global_asm!("{}", const 0 as *mut u8);
63+
//~^ ERROR mismatched types

‎src/test/ui/asm/type-check-1.stderr

+32-2
Original file line numberDiff line numberDiff line change
@@ -64,7 +64,37 @@ LL | asm!("{}", inout(reg) v[..]);
6464
= help: the trait `Sized` is not implemented for `[u64]`
6565
= note: all inline asm arguments must have a statically known size
6666

67-
error: aborting due to 8 previous errors
67+
error[E0308]: mismatched types
68+
--> $DIR/type-check-1.rs:48:26
69+
|
70+
LL | asm!("{}", const 0f32);
71+
| ^^^^ expected integer, found `f32`
72+
73+
error[E0308]: mismatched types
74+
--> $DIR/type-check-1.rs:50:26
75+
|
76+
LL | asm!("{}", const 0 as *mut u8);
77+
| ^^^^^^^^^^^^ expected integer, found *-ptr
78+
|
79+
= note: expected type `{integer}`
80+
found raw pointer `*mut u8`
81+
82+
error[E0308]: mismatched types
83+
--> $DIR/type-check-1.rs:60:25
84+
|
85+
LL | global_asm!("{}", const 0f32);
86+
| ^^^^ expected integer, found `f32`
87+
88+
error[E0308]: mismatched types
89+
--> $DIR/type-check-1.rs:62:25
90+
|
91+
LL | global_asm!("{}", const 0 as *mut u8);
92+
| ^^^^^^^^^^^^ expected integer, found *-ptr
93+
|
94+
= note: expected type `{integer}`
95+
found raw pointer `*mut u8`
96+
97+
error: aborting due to 12 previous errors
6898

69-
Some errors have detailed explanations: E0277, E0435.
99+
Some errors have detailed explanations: E0277, E0308, E0435.
70100
For more information about an error, try `rustc --explain E0277`.

‎src/test/ui/asm/type-check-2.rs

+1-17
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// only-x86_64
22

3-
#![feature(asm, global_asm, repr_simd, never_type)]
3+
#![feature(asm, repr_simd, never_type)]
44

55
#[repr(simd)]
66
struct SimdNonCopy(f32, f32, f32, f32);
@@ -26,14 +26,6 @@ fn main() {
2626
asm!("{}", inout(reg) v[0]);
2727
//~^ ERROR cannot borrow `v` as mutable, as it is not declared as mutable
2828

29-
// Const operands must be integer or floats, and must be constants.
30-
31-
asm!("{}", const 0);
32-
asm!("{}", const 0i32);
33-
asm!("{}", const 0f32);
34-
asm!("{}", const 0 as *mut u8);
35-
//~^ ERROR asm `const` arguments must be integer or floating-point values
36-
3729
// This currently causes an ICE: https://github.com/rust-lang/rust/issues/81857
3830
// asm!("{}", const &0);
3931
// ERROR asm `const` arguments must be integer or floating-point values
@@ -90,11 +82,3 @@ fn main() {
9082
asm!("{}", in(reg) u);
9183
}
9284
}
93-
94-
// Const operands must be integer or floats, and must be constants.
95-
96-
global_asm!("{}", const 0);
97-
global_asm!("{}", const 0i32);
98-
global_asm!("{}", const 0f32);
99-
global_asm!("{}", const 0 as *mut u8);
100-
//~^ ERROR asm `const` arguments must be integer or floating-point values

‎src/test/ui/asm/type-check-2.stderr

+11-23
Original file line numberDiff line numberDiff line change
@@ -1,27 +1,21 @@
1-
error: asm `const` arguments must be integer or floating-point values
2-
--> $DIR/type-check-2.rs:34:20
3-
|
4-
LL | asm!("{}", const 0 as *mut u8);
5-
| ^^^^^^^^^^^^^^^^^^
6-
71
error: arguments for inline assembly must be copyable
8-
--> $DIR/type-check-2.rs:54:32
2+
--> $DIR/type-check-2.rs:46:32
93
|
104
LL | asm!("{}", in(xmm_reg) SimdNonCopy(0.0, 0.0, 0.0, 0.0));
115
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
126
|
137
= note: `SimdNonCopy` does not implement the Copy trait
148

15-
error: cannot use value of type `[closure@$DIR/type-check-2.rs:66:28: 66:38]` for inline assembly
16-
--> $DIR/type-check-2.rs:66:28
9+
error: cannot use value of type `[closure@$DIR/type-check-2.rs:58:28: 58:38]` for inline assembly
10+
--> $DIR/type-check-2.rs:58:28
1711
|
1812
LL | asm!("{}", in(reg) |x: i32| x);
1913
| ^^^^^^^^^^
2014
|
2115
= note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
2216

2317
error: cannot use value of type `Vec<i32>` for inline assembly
24-
--> $DIR/type-check-2.rs:68:28
18+
--> $DIR/type-check-2.rs:60:28
2519
|
2620
LL | asm!("{}", in(reg) vec![0]);
2721
| ^^^^^^^
@@ -30,51 +24,45 @@ LL | asm!("{}", in(reg) vec![0]);
3024
= note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
3125

3226
error: cannot use value of type `(i32, i32, i32)` for inline assembly
33-
--> $DIR/type-check-2.rs:70:28
27+
--> $DIR/type-check-2.rs:62:28
3428
|
3529
LL | asm!("{}", in(reg) (1, 2, 3));
3630
| ^^^^^^^^^
3731
|
3832
= note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
3933

4034
error: cannot use value of type `[i32; 3]` for inline assembly
41-
--> $DIR/type-check-2.rs:72:28
35+
--> $DIR/type-check-2.rs:64:28
4236
|
4337
LL | asm!("{}", in(reg) [1, 2, 3]);
4438
| ^^^^^^^^^
4539
|
4640
= note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
4741

4842
error: cannot use value of type `fn() {main}` for inline assembly
49-
--> $DIR/type-check-2.rs:80:31
43+
--> $DIR/type-check-2.rs:72:31
5044
|
5145
LL | asm!("{}", inout(reg) f);
5246
| ^
5347
|
5448
= note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
5549

5650
error: cannot use value of type `&mut i32` for inline assembly
57-
--> $DIR/type-check-2.rs:83:31
51+
--> $DIR/type-check-2.rs:75:31
5852
|
5953
LL | asm!("{}", inout(reg) r);
6054
| ^
6155
|
6256
= note: only integers, floats, SIMD vectors, pointers and function pointers can be used as arguments for inline assembly
6357

64-
error: asm `const` arguments must be integer or floating-point values
65-
--> $DIR/type-check-2.rs:99:19
66-
|
67-
LL | global_asm!("{}", const 0 as *mut u8);
68-
| ^^^^^^^^^^^^^^^^^^
69-
7058
error: asm `sym` operand must point to a fn or static
71-
--> $DIR/type-check-2.rs:47:24
59+
--> $DIR/type-check-2.rs:39:24
7260
|
7361
LL | asm!("{}", sym C);
7462
| ^
7563

7664
error: asm `sym` operand must point to a fn or static
77-
--> $DIR/type-check-2.rs:49:24
65+
--> $DIR/type-check-2.rs:41:24
7866
|
7967
LL | asm!("{}", sym x);
8068
| ^
@@ -109,7 +97,7 @@ LL | let v: Vec<u64> = vec![0, 1, 2];
10997
LL | asm!("{}", inout(reg) v[0]);
11098
| ^ cannot borrow as mutable
11199

112-
error: aborting due to 15 previous errors
100+
error: aborting due to 13 previous errors
113101

114102
Some errors have detailed explanations: E0381, E0596.
115103
For more information about an error, try `rustc --explain E0381`.

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