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aarch64: Remove manual sign extension in lowering (#3538)

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Currently the lowering for `iconst` will sign-extend the payload value
of the `iconst` instruction itself, but the payload is already
sign-extended to this isn't necessary. This commit removes the redundant
sign extension.
This commit is contained in:
Alex Crichton
2021-11-16 16:47:12 -06:00
committed by GitHub
parent f30c8eb464
commit f787ce433d
1 changed files with 5 additions and 9 deletions
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14
cranelift/codegen/src/isa/aarch64/lower_inst.rs
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@@ -41,20 +41,16 @@ pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
match op {
Opcode::Iconst | Opcode::Bconst | Opcode::Null => {
let value = ctx.get_constant(insn).unwrap();
// Sign extend constant if necessary
let value = match ty.unwrap() {
I8 => (((value as i64) << 56) >> 56) as u64,
I16 => (((value as i64) << 48) >> 48) as u64,
I32 => (((value as i64) << 32) >> 32) as u64,
I64 | R64 => value,
ty if ty.is_bool() => value,
match ty.unwrap() {
I8 | I16 | I32 | I64 | R64 => {}
ty if ty.is_bool() => {}
ty => {
return Err(CodegenError::Unsupported(format!(
"{}: Unsupported type: {:?}",
op, ty
)))
)));
}
}
};
let rd = get_output_reg(ctx, outputs[0]).only_reg().unwrap();
lower_constant_u64(ctx, rd, value);
}