[PATCH, GCC/ARM] Fix PR85261: ICE with FPSCR setter builtin

[Thomas Preudhomme]

Instruction pattern for setting the FPSCR expects the input value to be
in a register. However, __builtin_arm_set_fpscr expander does not ensure
that this is the case and as a result GCC ICEs when the builtin is
called with a constant literal.

This commit fixes the builtin to force the input value into a register.
It also remove the unneeded volatile in the existing fpscr test and
fixes the function prototype.

ChangeLog entries are as follows:

*** gcc/ChangeLog ***

2018-04-06  Thomas Preud'homme  <thomas.preudhomme@arm.com>

	PR target/85261
	* config/arm/arm-builtins.c (arm_expand_builtin): Force input operand
	into register.

*** gcc/testsuite/ChangeLog ***

2018-04-06  Thomas Preud'homme  <thomas.preudhomme@arm.com>

	PR target/85261
	* gcc.target/arm/fpscr.c: Add call to __builtin_arm_set_fpscr with
	literal value.  Expect 2 MCR instruction.  Fix function prototype.
	Remove volatile keyword.

Testing: Built an arm-none-eabi GCC cross-compiler and testsuite shows
no regression.

Is this ok for stage4?

Best regards,

Thomas
-------------- next part --------------
A non-text attachment was scrubbed...
Name: fix_pr85261.patch
Type: text/x-patch
Size: 1334 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20180406/e2bab77a/attachment.bin>