diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs index 88a4f62d93d..2ef6fd4942b 100644 --- a/compiler/rustc_codegen_llvm/src/asm.rs +++ b/compiler/rustc_codegen_llvm/src/asm.rs @@ -505,6 +505,44 @@ fn xmm_reg_index(reg: InlineAsmReg) -> Option { } } +/// If the register is an AArch64 integer register then return its index. +fn a64_reg_index(reg: InlineAsmReg) -> Option { + match reg { + InlineAsmReg::AArch64(AArch64InlineAsmReg::x0) => Some(0), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x1) => Some(1), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x2) => Some(2), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x3) => Some(3), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x4) => Some(4), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x5) => Some(5), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x6) => Some(6), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x7) => Some(7), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x8) => Some(8), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x9) => Some(9), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x10) => Some(10), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x11) => Some(11), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x12) => Some(12), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x13) => Some(13), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x14) => Some(14), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x15) => Some(15), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x16) => Some(16), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x17) => Some(17), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x18) => Some(18), + // x19 is reserved + InlineAsmReg::AArch64(AArch64InlineAsmReg::x20) => Some(20), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x21) => Some(21), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x22) => Some(22), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x23) => Some(23), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x24) => Some(24), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x25) => Some(25), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x26) => Some(26), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x27) => Some(27), + InlineAsmReg::AArch64(AArch64InlineAsmReg::x28) => Some(28), + // x29 is reserved + InlineAsmReg::AArch64(AArch64InlineAsmReg::x30) => Some(30), + _ => None, + } +} + /// If the register is an AArch64 vector register then return its index. fn a64_vreg_index(reg: InlineAsmReg) -> Option { match reg { @@ -535,6 +573,22 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) -> 'x' }; format!("{{{}mm{}}}", class, idx) + } else if let Some(idx) = a64_reg_index(reg) { + let class = if let Some(layout) = layout { + match layout.size.bytes() { + 8 => 'x', + _ => 'w', + } + } else { + // We use i32 as the type for discarded outputs + 'w' + }; + if class == 'x' && reg == InlineAsmReg::AArch64(AArch64InlineAsmReg::x30) { + // LLVM doesn't recognize x30. use lr instead. + "{lr}".to_string() + } else { + format!("{{{}{}}}", class, idx) + } } else if let Some(idx) = a64_vreg_index(reg) { let class = if let Some(layout) = layout { match layout.size.bytes() { @@ -550,9 +604,6 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) -> 'q' }; format!("{{{}{}}}", class, idx) - } else if reg == InlineAsmReg::AArch64(AArch64InlineAsmReg::x30) { - // LLVM doesn't recognize x30 - "{lr}".to_string() } else if reg == InlineAsmReg::Arm(ArmInlineAsmReg::r14) { // LLVM doesn't recognize r14 "{lr}".to_string() diff --git a/src/test/ui/asm/aarch64/llvm-58384.rs b/src/test/ui/asm/aarch64/llvm-58384.rs new file mode 100644 index 00000000000..308f7890829 --- /dev/null +++ b/src/test/ui/asm/aarch64/llvm-58384.rs @@ -0,0 +1,16 @@ +// only-aarch64 +// run-pass +// needs-asm-support + +// Test that we properly work around this LLVM issue: +// https://github.com/llvm/llvm-project/issues/58384 + +use std::arch::asm; + +fn main() { + let a: i32; + unsafe { + asm!("", inout("x0") 435 => a); + } + assert_eq!(a, 435); +}