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Diffstat (limited to 'lib/Target/PowerPC/README.txt')
| -rw-r--r-- | lib/Target/PowerPC/README.txt | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README.txt b/lib/Target/PowerPC/README.txt index f5e50fc808..060d6a5c5c 100644 --- a/lib/Target/PowerPC/README.txt +++ b/lib/Target/PowerPC/README.txt @@ -7,6 +7,39 @@ TODO: ===-------------------------------------------------------------------------=== +On PPC64, this: + +long f2 (long x) { return 0xfffffff000000000UL; } +long f3 (long x) { return 0x1ffffffffUL; } + +could compile into: + +_f2: + li r3,-1 + rldicr r3,r3,0,27 + blr +_f3: + li r3,-1 + rldicl r3,r3,0,31 + blr + +we produce: + +_f2: + lis r2, 4095 + ori r2, r2, 65535 + sldi r3, r2, 36 + blr +_f3: + li r2, 1 + sldi r2, r2, 32 + oris r2, r2, 65535 + ori r3, r2, 65535 + blr + + +===-------------------------------------------------------------------------=== + Support 'update' load/store instructions. These are cracked on the G5, but are still a codesize win. |