> On Mon, Aug 17, 2015 at 11:29 AM, David Sherwood <david.sherw...@arm.com> > wrote: > > Hi Richard, > > > > Thanks for the reply. I'd chosen to add new expressions as this seemed more > > consistent with the existing MAX_EXPR and MIN_EXPR tree codes. In addition > > it > > would seem to provide more opportunities for optimisation than a > > target-specific > > builtin implementation would. I accept that optimisation opportunities will > > be more limited for strict math compilation, but that it was still worth > > having > > them. Also, if we did map it to builtins then the scalar version would go > > through the optabs and the vector version would go through the target's > > builtin > > expansion, which doesn't seem very consistent. > > On another note ISTR you can't associate STRICT_MIN/MAX_EXPR and thus > you can't vectorize anyway? (strict IEEE behavior is about NaNs, correct?) I thought for this particular case associativity wasn't an issue? We're not doing any reductions here, just simply performing max/min operations on each pair of elements in the vectors. I thought for IEEE-compliant behaviour we just need to ensure that for each pair of elements if one element is a NaN we return the other one.
David. > > Richard. > > > Regards, > > David. > > > >> -----Original Message----- > >> From: Richard Biener [mailto:richard.guent...@gmail.com] > >> Sent: 13 August 2015 12:10 > >> To: David Sherwood > >> Cc: GCC Patches > >> Subject: Re: [PING][Patch] Add support for IEEE-conformant versions of > >> scalar fmin* and fmax* > >> > >> On Thu, Aug 13, 2015 at 12:11 PM, David Sherwood <david.sherw...@arm.com> > >> wrote: > >> > Hi, > >> > > >> > Sorry to bother people again. Is this OK to go now? > >> > >> Hmm, why don't you go the vectorized function call path for this, > >> implementing the builtin_vectorized_function target hook? > >> > >> Richard. > >> > >> > Thanks! > >> > David. > >> > > >> >> > > >> >> > > On Mon, 29 Jun 2015, David Sherwood wrote: > >> >> > > > >> >> > > > Hi, > >> >> > > > > >> >> > > > I have added new STRICT_MAX_EXPR and STRICT_MIN_EXPR expressions > >> >> > > > to support the > >> >> > > > IEEE versions of fmin and fmax. This is done by recognising the > >> >> > > > math library > >> >> > > > "fmax" and "fmin" builtin functions in a similar way to how this > >> >> > > > is done for > >> >> > > > -ffast-math. This also allows us to vectorise the IEEE max/min > >> >> > > > functions for > >> >> > > > targets that support it, for example aarch64/aarch32. > >> >> > > > >> >> > > This patch is missing documentation. You need to document the new > >> >> > > insn > >> >> > > patterns in md.texi and the new tree codes in generic.texi. > >> >> > > >> >> > Hi, I've uploaded a new patch with the documentation. Hope this is ok. > >> >> > >> >> In various places where you refer to one operand being NaN, I think you > >> >> mean one operand being a *quiet* NaN (if one is a signaling NaN - only > >> >> supported by GCC if -fsignaling-nans - the IEEE minNum and maxNum > >> >> operations raise "invalid" and return a quiet NaN). > >> > > >> > Hi, I have a new patch that hopefully addresses the documentation issues. > >> > > >> > Thanks, > >> > David. > >> > > >> > ChangeLog: > >> > > >> > 2015-07-15 David Sherwood <david.sherw...@arm.com> > >> > > >> > gcc/ > >> > * builtins.c (integer_valued_real_p): Add STRICT_MIN_EXPR and > >> > STRICT_MAX_EXPR. > >> > (fold_builtin_fmin_fmax): For strict math, convert builting fmin and > >> > fmax to STRICT_MIN_EXPR and STRICT_MIN_EXPR, respectively. > >> > * expr.c (expand_expr_real_2): Add STRICT_MIN_EXPR and > >> > STRICT_MAX_EXPR. > >> > * fold-const.c (const_binop): Likewise. > >> > (fold_binary_loc, tree_binary_nonnegative_warnv_p): Likewise. > >> > (tree_binary_nonzero_warnv_p): Likewise. > >> > * optabs.h (strict_minmax_support): Declare. > >> > * optabs.def: Add new optabs strict_max_optab/strict_min_optab. > >> > * optabs.c (optab_for_tree_code): Return new optabs for > >> > STRICT_MIN_EXPR > >> > and STRICT_MAX_EXPR. > >> > (strict_minmax_support): New function. > >> > * real.c (real_arithmetic): Add STRICT_MIN_EXPR and STRICT_MAX_EXPR. > >> > * tree.def: Likewise. > >> > * tree.c (associative_tree_code, commutative_tree_code): Likewise. > >> > * tree-cfg.c (verify_expr): Likewise. > >> > (verify_gimple_assign_binary): Likewise. > >> > * tree-inline.c (estimate_operator_cost): Likewise. > >> > * tree-pretty-print.c (dump_generic_node, op_code_prio): Likewise. > >> > (op_symbol_code): Likewise. > >> > gcc/config: > >> > * aarch64/aarch64.md: New pattern. > >> > * aarch64/aarch64-simd.md: Likewise. > >> > * aarch64/iterators.md: New unspecs, iterators. > >> > * arm/iterators.md: New iterators. > >> > * arm/unspecs.md: New unspecs. > >> > * arm/neon.md: New pattern. > >> > * arm/vfp.md: Likewise. > >> > gcc/doc: > >> > * generic.texi: Add STRICT_MAX_EXPR and STRICT_MIN_EXPR. > >> > * md.texi: Add strict_min and strict_max patterns. > >> > gcc/testsuite > >> > * gcc.target/aarch64/maxmin_strict.c: New test. > >> > * gcc.target/arm/maxmin_strict.c: New test. > > > > > >
