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Remove the reg_thumb register class for asm! on ARM
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Also restricts r8-r14 from being used on Thumb1 targets as per rust-lang#90736.
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Amanieu committed Dec 7, 2021
1 parent 0b6f079 commit 908f300
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Showing 8 changed files with 30 additions and 65 deletions.
7 changes: 2 additions & 5 deletions compiler/rustc_codegen_gcc/src/asm.rs
Original file line number Diff line number Diff line change
Expand Up @@ -568,7 +568,6 @@ fn reg_to_gcc(reg: InlineAsmRegOrRegClass) -> ConstraintOrRegister {
InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) => unimplemented!(),
InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8) => unimplemented!(),
Expand Down Expand Up @@ -628,8 +627,7 @@ fn dummy_output_type<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, reg: InlineAsmRegCl
| InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => {
unimplemented!()
}
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => cx.type_i32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg)=> cx.type_i32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => cx.type_f32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
Expand Down Expand Up @@ -737,8 +735,7 @@ fn modifier_to_gcc(arch: InlineAsmArch, reg: InlineAsmRegClass, modifier: Option
| InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => {
unimplemented!()
}
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => unimplemented!(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
Expand Down
7 changes: 2 additions & 5 deletions compiler/rustc_codegen_llvm/src/asm.rs
Original file line number Diff line number Diff line change
Expand Up @@ -632,7 +632,6 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'tcx>>)
unreachable!("clobber-only")
}
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => "r",
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => "l",
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8) => "t",
Expand Down Expand Up @@ -703,8 +702,7 @@ fn modifier_to_llvm(
InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => {
unreachable!("clobber-only")
}
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => None,
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => None,
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => None,
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
Expand Down Expand Up @@ -785,8 +783,7 @@ fn dummy_output_type(cx: &CodegenCx<'ll, 'tcx>, reg: InlineAsmRegClass) -> &'ll
InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => {
unreachable!("clobber-only")
}
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg_thumb) => cx.type_i32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => cx.type_i32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg)
| InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => cx.type_f32(),
InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg)
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_codegen_ssa/src/target_features.rs
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@ const ARM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
// since it should be enabled per-function using #[instruction_set], not
// #[target_feature].
("thumb-mode", Some(sym::arm_target_feature)),
("thumb2", Some(sym::arm_target_feature)),
];

const AARCH64_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
Expand Down
1 change: 0 additions & 1 deletion compiler/rustc_span/src/symbol.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1057,7 +1057,6 @@ symbols! {
reg_nonzero,
reg_pair,
reg_ptr,
reg_thumb,
reg_upper,
register_attr,
register_tool,
Expand Down
37 changes: 24 additions & 13 deletions compiler/rustc_target/src/asm/arm.rs
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,6 @@ use std::fmt;
def_reg_class! {
Arm ArmInlineAsmRegClass {
reg,
reg_thumb,
sreg,
sreg_low16,
dreg,
Expand Down Expand Up @@ -47,7 +46,7 @@ impl ArmInlineAsmRegClass {
_arch: InlineAsmArch,
) -> &'static [(InlineAsmType, Option<&'static str>)] {
match self {
Self::reg | Self::reg_thumb => types! { _: I8, I16, I32, F32; },
Self::reg => types! { _: I8, I16, I32, F32; },
Self::sreg | Self::sreg_low16 => types! { "vfp2": I32, F32; },
Self::dreg | Self::dreg_low16 | Self::dreg_low8 => types! {
"vfp2": I64, F64, VecI8(8), VecI16(4), VecI32(2), VecI64(1), VecF32(2);
Expand Down Expand Up @@ -88,20 +87,32 @@ fn frame_pointer_r7(
}
}

fn not_thumb1(
_arch: InlineAsmArch,
mut has_feature: impl FnMut(&str) -> bool,
_target: &Target,
) -> Result<(), &'static str> {
if has_feature("thumb-mode") && !has_feature("thumb2") {
Err("high registers (r8+) cannot be used in Thumb-1 code")
} else {
Ok(())
}
}

def_regs! {
Arm ArmInlineAsmReg ArmInlineAsmRegClass {
r0: reg, reg_thumb = ["r0", "a1"],
r1: reg, reg_thumb = ["r1", "a2"],
r2: reg, reg_thumb = ["r2", "a3"],
r3: reg, reg_thumb = ["r3", "a4"],
r4: reg, reg_thumb = ["r4", "v1"],
r5: reg, reg_thumb = ["r5", "v2"],
r7: reg, reg_thumb = ["r7", "v4"] % frame_pointer_r7,
r8: reg = ["r8", "v5"],
r10: reg = ["r10", "sl"],
r0: reg = ["r0", "a1"],
r1: reg = ["r1", "a2"],
r2: reg = ["r2", "a3"],
r3: reg = ["r3", "a4"],
r4: reg = ["r4", "v1"],
r5: reg = ["r5", "v2"],
r7: reg = ["r7", "v4"] % frame_pointer_r7,
r8: reg = ["r8", "v5"] % not_thumb1,
r10: reg = ["r10", "sl"] % not_thumb1,
r11: reg = ["r11", "fp"] % frame_pointer_r11,
r12: reg = ["r12", "ip"],
r14: reg = ["r14", "lr"],
r12: reg = ["r12", "ip"] % not_thumb1,
r14: reg = ["r14", "lr"] % not_thumb1,
s0: sreg, sreg_low16 = ["s0"],
s1: sreg, sreg_low16 = ["s1"],
s2: sreg, sreg_low16 = ["s2"],
Expand Down
6 changes: 1 addition & 5 deletions src/doc/unstable-book/src/library-features/asm.md
Original file line number Diff line number Diff line change
Expand Up @@ -564,12 +564,8 @@ Here is the list of currently supported register classes:
| AArch64 | `vreg` | `v[0-31]` | `w` |
| AArch64 | `vreg_low16` | `v[0-15]` | `x` |
| AArch64 | `preg` | `p[0-15]`, `ffr` | Only clobbers |
| ARM (ARM) | `reg` | `r[0-12]`, `r14` | `r` |
| ARM (Thumb2) | `reg` | `r[0-12]`, `r14` | `r` |
| ARM (ARM/Thumb2) | `reg` | `r[0-12]`, `r14` | `r` |
| ARM (Thumb1) | `reg` | `r[0-7]` | `r` |
| ARM (ARM) | `reg_thumb` | `r[0-r12]`, `r14` | `l` |
| ARM (Thumb2) | `reg_thumb` | `r[0-7]` | `l` |
| ARM (Thumb1) | `reg_thumb` | `r[0-7]` | `l` |
| ARM | `sreg` | `s[0-31]` | `t` |
| ARM | `sreg_low16` | `s[0-15]` | `x` |
| ARM | `dreg` | `d[0-31]` | `w` |
Expand Down
6 changes: 0 additions & 6 deletions src/test/assembly/asm/arm-modifiers.rs
Original file line number Diff line number Diff line change
Expand Up @@ -59,12 +59,6 @@ macro_rules! check {
// CHECK: @NO_APP
check!(reg "" reg i32 "mov");

// CHECK-LABEL: reg_thumb:
// CHECK: @APP
// CHECK: mov r0, r0
// CHECK: @NO_APP
check!(reg_thumb "" reg_thumb i32 "mov");

// CHECK-LABEL: sreg:
// CHECK: @APP
// CHECK: vmov.f32 s0, s0
Expand Down
30 changes: 0 additions & 30 deletions src/test/assembly/asm/arm-types.rs
Original file line number Diff line number Diff line change
Expand Up @@ -163,36 +163,6 @@ check!(reg_f32 f32 reg "mov");
// CHECK: @NO_APP
check!(reg_ptr ptr reg "mov");

// CHECK-LABEL: reg_thumb_i8:
// CHECK: @APP
// CHECK: mov {{[a-z0-9]+}}, {{[a-z0-9]+}}
// CHECK: @NO_APP
check!(reg_thumb_i8 i8 reg_thumb "mov");

// CHECK-LABEL: reg_thumb_i16:
// CHECK: @APP
// CHECK: mov {{[a-z0-9]+}}, {{[a-z0-9]+}}
// CHECK: @NO_APP
check!(reg_thumb_i16 i16 reg_thumb "mov");

// CHECK-LABEL: reg_thumb_i32:
// CHECK: @APP
// CHECK: mov {{[a-z0-9]+}}, {{[a-z0-9]+}}
// CHECK: @NO_APP
check!(reg_thumb_i32 i32 reg_thumb "mov");

// CHECK-LABEL: reg_thumb_f32:
// CHECK: @APP
// CHECK: mov {{[a-z0-9]+}}, {{[a-z0-9]+}}
// CHECK: @NO_APP
check!(reg_thumb_f32 f32 reg_thumb "mov");

// CHECK-LABEL: reg_thumb_ptr:
// CHECK: @APP
// CHECK: mov {{[a-z0-9]+}}, {{[a-z0-9]+}}
// CHECK: @NO_APP
check!(reg_thumb_ptr ptr reg_thumb "mov");

// CHECK-LABEL: sreg_i32:
// CHECK: @APP
// CHECK: vmov.f32 s{{[0-9]+}}, s{{[0-9]+}}
Expand Down

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