Re: [PR86438] compare-elim: cope with set of in_b

2018-11-09 Thread Alexandre Oliva
On Nov 8, 2018, Jeff Law wrote: >> PR rtl-optimization/86438 >> * gcc.dg/torture/pr86438.c: New. > OK. Thanks. I ended up tweaking the test a bit further, when it occurred to me that I might be able to trigger the same problem with -m32, but no such luck. Here's the test I'm installing, inste

Re: [PR86438] compare-elim: cope with set of in_b

2018-11-08 Thread Jeff Law
On 11/8/18 4:00 AM, Alexandre Oliva wrote: > When in_a resolves to a register set in the prev_clobber insn, we may > use the SET_SRC for the compare instead. However, when in_b so > resolves, we proceed to use the reg with its earlier value. When both > resolve to the same register and prev_clobb

[PR86438] compare-elim: cope with set of in_b

2018-11-08 Thread Alexandre Oliva
When in_a resolves to a register set in the prev_clobber insn, we may use the SET_SRC for the compare instead. However, when in_b so resolves, we proceed to use the reg with its earlier value. When both resolve to the same register and prev_clobber is an insn that modifies the register, this arra