Local optimization fixes for diverences found by self verification.
1) Only optimize each block once. Strictly speaking this is not a
correctness issue however it triggers the subsequent problem.
2) Ignore dead instructions.
1: ldr r2, [r5, #8]
2: ldr r3, [r5, #8](nop)
3: str r3, [r5, #4]
4: movs r3, r2
When using instruction 1 to initiate redundant ld/st eliminations, if
instruction 2 (which is already dead) is not ignored, it will be turned
into a "mov r3, r2" and that will clobber r3 used by the str.
Change-Id: I6b9a88d3688889d917b90f4b8f55278df1701c6a
2 files changed