Jim Grosbach 94dfd6fc4f Simplify ARM callee-saved register handling by removing the distinction ...

between the high and low registers for prologue/epilogue code. This was
a Darwin-only thing that wasn't providing a realistic benefit anymore.
Combining the save areas simplifies the compiler code and results in better
ARM/Thumb2 codegen.

For example, previously we would generate code like:
        push    {r4, r5, r6, r7, lr}
        add     r7, sp, #12
        stmdb   sp!, {r8, r10, r11}
With this change, we combine the register saves and generate:
        push    {r4, r5, r6, r7, r8, r10, r11, lr}
        add     r7, sp, #12

rdar://8445635

llvm-svn: 114340

2010-09-20 19:32:20 +00:00

2.4 KiB

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