As mentioned in PR65768, ARM gcc generates suboptimal code for constant
Uses in loop. Part of the reason is that ARM back-end is splitting
constants during expansion of RTL, making it hard for the RTL
optimization passes to optimize it. Zhenqiang posted a patch at
https://gcc.gnu.org/ml/gcc-patches/2014-08/msg00325.html to fix this

As mentioned in PR65768, I tried with few more test-cases and enhanced
it. Regression tested on arm-none-linux-gnu and no new regressions. Is
this OK for trunk?

Thanks,
Kugan


gcc/ChangeLog:

2015-04-15  Kugan Vivekanandarajah  <kuganv@linaro.org>
	    Zhenqiang Chen  <zhenqiang.chen@linaro.org>

	PR target/65768
	* config/arm/arm-protos.h (const_ok_for_split): New definition.
	* config/arm/arm.c (const_ok_for_split): New function.
	* config/arm/arm.md (subsi3, andsi3, iorsi3, xorsi3, movsi): Keep some
	 large constants in register instead of splitting them.

gcc/testsuite/ChangeLog:

2015-04-15  Kugan Vivekanandarajah  <kuganv@linaro.org>
	    Zhenqiang Chen  <zhenqiang.chen@linaro.org>

	PR target/65768
	* gcc.target/arm/maskdata.c: New test.