On Tue, Aug 18, 2015 at 1:07 PM, David Sherwood <david.sherw...@arm.com> wrote: >> 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.
Hmm, true. Ok, my comment still stands - I don't see that using a tree code is the best thing to do here. You can add fmin/max optabs and special expansion of BUILT_IN_FMIN/MAX and you can use a target builtin for the vectorized variant. The reason I am pushing against a new tree code is that we'd have an awful lot of similar codes when pushing other flag related IL specialities to actual IL constructs. And we still need to find a consistent way to do that. Richard. > 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. >> > >> > >> > > > >
