Tag_CPU_name merging produces wrong tag for ARM.

[Maxim Ostapenko]

Add Andrew Stubbs  and Nick Clifton as author and reviewer of ARM 
attributes merging patch ( 
https://sourceware.org/ml/binutils/2009-01/msg00156.html).

-------- Original Message --------
Subject: 	[Bug ld/17212] Tag_CPU_name merging produces wrong tag for ARM.
Date: 	Tue, 02 Sep 2014 13:19:20 +0400
From: 	Maxim Ostapenko <m.ostapenko@partner.samsung.com>
To: 	binutils@sourceware.org
CC: 	Yury Gribov <y.gribov@samsung.com>, Slava Garbuzov 
<v.garbuzov@samsung.com>



Hi,

I tried to compile a binary optimized for ARM Cortex-A15 with ARM
Cortex-A8 cross-toolchain (host is x86_64-pc-linux-gnu), but
Tag_CPU_name appears to be "Cortex-A8" for the binary instead of
"Cortex-A15". The example session follows:

$ arm-v7a8-linux-gnueabi-gcc -O2 -mcpu=cortex-a15 divtest.c -o divtest.a15

$ readelf -A divtest.a15

Attribute Section: aeabi
File Attributes
Tag_CPU_name: "Cortex-A8"
Tag_CPU_arch: v7
................................................
Tag_DIV_use: Allowed in v7-A with integer division extension

After some investigation I found out, that Tag_CPU_name merging based on
Tag_CPU_arch. Since the first file to appear during linking is crt1.o,
which has Tag_CPU_name: "Cortex-A8" for A8 toolchain, the result
binary's Tag_CPU_name is also "Cortex-A8". Is this expected behavior of
ld, or maybe tags should be merged to a more specific "Cortex-A15"?
Perhaps we should use Tag_DIV_use when merging names?

-Maxim