On 09/06/2017 03:54 AM, Jackson Woodruff wrote: > Hi all, > > This patch is split from part (1/2). It includes the patterns that have > been moved out of fold-const.c > > > It also removes an (almost entirely) redundant pattern: > > (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2) > > which was only used in special cases, either with combinations > of flags like -fno-reciprocal-math -funsafe-math-optimizations > and cases where C was sNaN, or small enough to result in infinity. > > This pattern is covered by: > > (A / C1) +- (A / C2) -> (with O1 and reciprocal math) > A * (1 / C1) +- A * (1 / C2) -> > A * (1 / C1 +- 1 / C2) > > The previous pattern required funsafe-math-optimizations. > > To adjust for this case, the testcase has been updated to require O1 so > that the optimization is still performed. > > > This pattern is moved verbatim into match.pd: > > (A / C) +- (B / C) -> (A +- B) / C. > > OK for trunk? > > Jackson > > gcc/ > > 2017-08-30 Jackson Woodruff <jackson.woodr...@arm.com> > > PR 71026/tree-optimization > * match.pd: Move RDIV patterns from fold-const.c > * fold-const.c (distribute_real_division): Removed. > (fold_binary_loc): Remove calls to distribute_real_divison. > > gcc/testsuite/ > > 2017-08-30 Jackson Woodruff <jackson.woodr...@arm.com> > > PR 71026/tree-optimization > * gcc/testsuire/gcc.dg/fold-div-1.c: Use O1.
Didn't you lose the case where the operator is MULT_EXPR rather than RDIV_EXPR? If I'm reading things correctly, arg0 and arg1 could be a RDIV_EXPR or a MULT_EXPR and we distribute both cases (as long as they are both the same code). Your match.pd pattern only handle rdiv. Now it may be the case that MULT_EXPR doesn't happen anymore in practice -- the code in fold-const is quote old and much of it was written before we regularly added tests for optimization and canonicalization. So I'm not surprised nothing in this testsuite trips over this omission. ISTM you need to either argue that the MULT_EXPR case is handled elsewhere or that it is no longer relevant. jeff
