[Patch, Gas, AArch64][2/2] Fix Diagnostic messaging for LD/ST Exclusive.

[Tejas Belagod]

Hi,

A summary of what this patch set fixes:

For instructions
STXR w0,x2,[x0]
STLXR w0,x2,[x0]

The warning we emit currently is misleading:

t.s:9: Warning: unpredictable: identical transfer and status registers --`stlxr w0,x2,[x0]'
t.s:10: Warning: unpredictable: identical transfer and status registers --`stxr w0,x2,[x0]'

it ought to be:

t.s:9: Warning: unpredictable: identical base and status registers --`stlxr w0,x2,[x0]'
t.s:10: Warning: unpredictable: identical base and status registers --`stxr w0,x2,[x0]'

For instructions:
ldaxp x0,x0,[x0]
ldxp x0,x0,[x0]

The warning we emit is incorrect

t.s:11: Warning: unpredictable: identical transfer and status registers --`ldaxp x0,x0,[x0]'
t.s:12: Warning: unpredictable: identical transfer and status registers --`ldxp x0,x0,[x0]'

it ought to be:

Warning: unpredictable load of register pair -- `ldaxp x0,x0,[x0]'
Warning: unpredictable load of register pair -- `ldxp x0,x0,[x0]'

For instructions
        stlxp   w0, x2, x2, [x0]
        stxp    w0, x2, x2, [x0]

We don't emit any warning when it ought to be:

t.s:13: Warning: unpredictable: identical base and status registers --`stlxp w0,x2,x2,[x0]'
t.s:14: Warning: unpredictable: identical base and status registers --`stxp w0,x2,x2,[x0]'

Tested on master binutils with make check. OK for master?

Thanks,
Tejas.

gas/ChangeLog:

2021-03-11  Tejas Belagod  <tejas.belagod@arm.com>

	* config/tc-aarch64.c (warn_unpredictable_ldst): Clean-up diagnostic messages
	for LD/ST Exclusive instructions.

gas/testsuite/ChangeLog:

2021-03-11  Tejas Belagod  <tejas.belagod@arm.com>

	* gas/aarch64/diagnostic.s: Add a diagnostic test for STLXP.
	* gas/aarch64/diagnostic.l: Fix-up test after message clean-up.
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: diag.txt
URL: <https://sourceware.org/pipermail/binutils/attachments/20210315/84279cbf/attachment-0001.txt>