On 6/14/19 6:51 AM, Jiufu Guo wrote: > Jeff Law <l...@redhat.com> writes: > >> On 6/3/19 11:28 PM, Jiufu Guo wrote: >>> >>> Hi, >>> >>> This patch implements a new opportunity of jump threading for PR77820. >>> In this optimization, conditional jumps are merged with unconditional >>> jump. And then moving CMP result to GPR is eliminated. >>> >>> This version is based on the proposal of Richard, Jeff and Andrew on >>> previous versions, and refined to incorporate comments, such as accept >>> the path with single_succ_p (e->src). >>> Thanks for the reviews! >>> >>> Bootstrapped and tested on powerpc64le, powerpc64 and sh (with help >>> from Jeff) with no regressions (two cases are improved and updated >>> to keep original test coverage) and new testcases are added. >>> Is this ok for trunk? >>> >>> Example of this opportunity looks like below: >>> >>> <P0> >>> p0 = a CMP b >>> goto <X>; >>> >>> <P1> >>> p1 = c CMP d >>> goto <X>; >>> >>> <X> >>> # phi = PHI <p0 (P0), p1 (P1)> >>> if (phi != 0) goto <Y>; else goto <Z>; >>> >>> Could be transformed to: >>> >>> <P0> >>> p0 = a CMP b >>> if (p0 != 0) goto <Y>; else goto <Z>; >>> >>> <P1> >>> p1 = c CMP d >>> if (p1 != 0) goto <Y>; else goto <Z>; >>> >>> >>> This optimization eliminates: >>> 1. saving CMP result: p0 = a CMP b. >>> 2. additional CMP on branch: if (phi != 0). >>> 3. converting CMP result if there is phi = (INT) p0 if there is. >>> >>> Thanks! >>> Jiufu Guo >>> >>> [gcc] >>> 2019-06-04 Jiufu Guo <guoji...@linux.ibm.com> >>> Lijia He <heli...@linux.ibm.com> >>> >>> PR tree-optimization/77820 >>> * tree-ssa-threadedge.c >>> (edge_forwards_cmp_to_conditional_jump_through_empty_bb_p): New >>> function. >>> (thread_across_edge): Add call to >>> edge_forwards_cmp_to_conditional_jump_through_empty_bb_p. >>> >>> [gcc/testsuite] >>> 2019-06-04 Jiufu Guo <guoji...@linux.ibm.com> >>> Lijia He <heli...@linux.ibm.com> >>> >>> PR tree-optimization/77820 >>> * gcc.dg/tree-ssa/phi_on_compare-1.c: New testcase. >>> * gcc.dg/tree-ssa/phi_on_compare-2.c: New testcase. >>> * gcc.dg/tree-ssa/phi_on_compare-3.c: New testcase. >>> * gcc.dg/tree-ssa/phi_on_compare-4.c: New testcase. >>> * gcc.dg/tree-ssa/split-path-6.c: Update testcase. >>> * gcc.target/sh/pr51244-20.c: Update testcase. >> Yes, this is OK for the trunk. I'll commit it momentarily. > Thanks Jeff! I got svn access, I could commit next time. Yea, Segher pointed that out to me in IRC. Looking forward to your next patchkit :-)
jeff
