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SubjectRe: {standard input}:136: Error: number (0x9000000080000000) larger than 32 bits
On Mon, 18 Apr 2016, Ralf Baechle wrote:

> I extracted a rather simple test case:
>
> $ echo >> testcase .s << EOF
> .set mips3
> dli $2, 0x9000000080000000
> EOF
> $ mips-linux-as -mips3 -march=r4600 -o testcase.o testcase.s
> testcase.s: Assembler messages:
> testcase.s:2: Error: number (0x9000000080000000) larger than 32 bits
> $ mips-linux-as -mips4 -march=vr5000 -o testcase.o testcase.s
> $

Ah, and if you use `.set mips4' instead, then the symptoms reverse.

The thing is that to match some software's (such as ours) requirements an
ISA override -- as a side effect -- relaxes ABI restrictions on certain
operations. E.g. the DLI macro and its 64-bit immediate argument are not
valid in the o32 ABI. When no actual override happens, such as with
`-march=r4600' which already implies `mips3' for the ISA, the side effect
is lost:

/* The use of .set [arch|cpu]= historically 'fixes' the width of gp and fp
registers based on what is supported by the arch/cpu. */
if (mips_opts.isa != prev_isa)

> I can trigger the error message with vanilla 2.25 and 2.26 but not 2.24.

The regression has come with:

commit 919731affbef19fcad8dddb0a595bb05755cb345
Author: mfortune <matthew.fortune@imgtec.com>
Date: Tue May 20 13:28:20 2014 +0100

Add MIPS .module directive

-- previously the side effect was unconditional, even if no ISA change
resulted.

Matthew, this functional change was not mentioned in the review:
<https://sourceware.org/ml/binutils/2014-05/msg00179.html> -- what was the
rationale behind it? Do you expect any issues if we revert to old
semantics?

Maciej

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