[Patch, ARM] Fix the check on arg reg number in function thumb_find_work_register

[Terry Guo]

Hello,

Attached patch intends to fix a bug on how to check argument register number
which should consider the PCS. A test case is also included. Without this
fix, one of the function argument will be overridden in the case. Tested on
QEMU for cortex-m3, no regression found. Is it OK to trunk?

BR,
Terry

gcc/ChangeLog:

2012-11-28  Terry Guo  <terry....@arm.com>

        * config/arm/arm.c (thumb_find_work_register): Check
        argument register number based on current PCS.

gcc/testsuite/ChangeLog:

2012-11-28  Terry Guo  <terry....@arm.com>

        * gcc.target/arm/thumb-find-work-register.c: New.

fix-thumb-find-work-register.patch
Description: Binary data