Armv7-M: Removing the wrong args_in_out_different for ldr/ldrb/ldrh
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- This commit removes the restriction in the `make()` function of `ldr`, `ldr_with_imm`, `ldrb_with_imm` and `ldrh_with_imm`, namely the line: `obj.args_in_out_different = [(0, 0)] # Can't have Rd==Ra`. - This restriction makes it harder for Slothy to find a solution in scenarios where the number of available registers was limited. Signed-off-by: willieyz <[email protected]>
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mkannwischer
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Nov 19, 2025
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LGTM. Thanks @willieyz.
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args_in_out_differentargs_in_out_different for ldr/ldrb/ldrh
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We discovered this issue during Add instruction support for Curve25519 armv7-M optimization tasks #341, when we tried to optimize some assembly code that included
ldrinstructions. Theargs_in_out_differentrestriction made it harder for Slothy to find a solution in scenarios where the number of available registers was limited.This PR removes the restriction in the
make()function ofldrandldr_with_imm, namely the line:obj.args_in_out_different = [(0, 0)] # Can't have Rd==Ra.we believe this is wrong restriction for
ldr,ldr_imm,ldrh_with_immandldrb_with_imm