Commit Graph

3 Commits

Author SHA1 Message Date
Jim Grosbach
1dc335a79f 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



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114340 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-20 19:32:20 +00:00
Evan Cheng
3ef1c8759a Teach if-converter to be more careful with predicating instructions that would
take multiple cycles to decode.
For the current if-converter clients (actually only ARM), the instructions that
are predicated on false are not nops. They would still take machine cycles to
decode. Micro-coded instructions such as LDM / STM can potentially take multiple
cycles to decode. If-converter should take treat them as non-micro-coded
simple instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113570 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-10 01:29:16 +00:00
Evan Cheng
4d54e5b2dd Tail merging pass shall not break up IT blocks. rdar://8115404
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106517 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-22 01:18:16 +00:00