This patch exploits rldimi instruction for patterns like
`or %a, 0b000011110000`, which saves number of instructions when the
operand has only one use, compared with `li-ori-sldi-or`.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D77850
- recommitting after fixing a test failure on MacOS
On PPC64, OR (XOR) with a 32-bit immediate can be done with only two instructions, i.e. ori + oris.
But the current LLVM generates three or four instructions for this purpose (and also it clobbers one GPR).
This patch makes PPC backend generate ori + oris (xori + xoris) for OR (XOR) with a 32-bit immediate.
e.g. (x | 0xFFFFFFFF) should be
ori 3, 3, 65535
oris 3, 3, 65535
but LLVM generates without this patch
li 4, 0
oris 4, 4, 65535
ori 4, 4, 65535
or 3, 3, 4
Differential Revision: https://reviews.llvm.org/D34757
llvm-svn: 311538
On PPC64, OR (XOR) with a 32-bit immediate can be done with only two instructions, i.e. ori + oris.
But the current LLVM generates three or four instructions for this purpose (and also it clobbers one GPR).
This patch makes PPC backend generate ori + oris (xori + xoris) for OR (XOR) with a 32-bit immediate.
e.g. (x | 0xFFFFFFFF) should be
ori 3, 3, 65535
oris 3, 3, 65535
but LLVM generates without this patch
li 4, 0
oris 4, 4, 65535
ori 4, 4, 65535
or 3, 3, 4
Differential Revision: https://reviews.llvm.org/D34757
llvm-svn: 311526
Qiu Chaofan