On Sat, Feb 10, 2018 at 03:26:46PM +0100, Jakub Jelinek wrote:
> If use_exp2 is true and (cfun->curr_properties & PROP_gimple_lvec) == 0,
> don't fold it? Then I guess if we vectorize or slp vectorize the pow
> as vector pow, we'd need to match.pd it into the exp (log (vec_cst) * x).
Here is an updated patch, that defers it for pow (0x2.0pN, x) until after
vectorization and adds tree-vect-patterns.c matcher that will handle it
during vectorization (that one using exp, because we don't have exp2
vectorized).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2018-02-12 Jakub Jelinek <ja...@redhat.com>
PR middle-end/84309
* match.pd (pow(C,x) -> exp(log(C)*x)): Optimize instead into
exp2(log2(C)*x) if C is a power of 2 and c99 runtime is available.
* generic-match-head.c (canonicalize_math_after_vectorization_p): New
inline function.
* gimple-match-head.c (canonicalize_math_after_vectorization_p): New
inline function.
* omp-simd-clone.h: New file.
* omp-simd-clone.c: Include omp-simd-clone.h.
(expand_simd_clones): No longer static.
* tree-vect-patterns.c: Include fold-const-call.h, attribs.h,
cgraph.h and omp-simd-clone.h.
(vect_recog_pow_pattern): Optimize pow(C,x) to exp(log(C)*x).
(vect_recog_widen_shift_pattern): Formatting fix.
(vect_pattern_recog_1): Don't check optab for calls.
* gcc.dg/pr84309.c: New test.
* gcc.target/i386/pr84309.c: New test.
--- gcc/match.pd.jj 2018-02-09 19:11:26.910070491 +0100
+++ gcc/match.pd 2018-02-12 14:15:05.653779352 +0100
@@ -3992,15 +3992,36 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(logs (pows @0 @1))
(mult @1 (logs @0))))
- /* pow(C,x) -> exp(log(C)*x) if C > 0. */
+ /* pow(C,x) -> exp(log(C)*x) if C > 0,
+ or if C is a positive power of 2,
+ pow(C,x) -> exp2(log2(C)*x). */
(for pows (POW)
exps (EXP)
logs (LOG)
+ exp2s (EXP2)
+ log2s (LOG2)
(simplify
(pows REAL_CST@0 @1)
- (if (real_compare (GT_EXPR, TREE_REAL_CST_PTR (@0), &dconst0)
- && real_isfinite (TREE_REAL_CST_PTR (@0)))
- (exps (mult (logs @0) @1)))))
+ (if (real_compare (GT_EXPR, TREE_REAL_CST_PTR (@0), &dconst0)
+ && real_isfinite (TREE_REAL_CST_PTR (@0)))
+ (with {
+ const REAL_VALUE_TYPE *const value = TREE_REAL_CST_PTR (@0);
+ bool use_exp2 = false;
+ if (targetm.libc_has_function (function_c99_misc)
+ && value->cl == rvc_normal)
+ {
+ REAL_VALUE_TYPE frac_rvt = *value;
+ SET_REAL_EXP (&frac_rvt, 1);
+ if (real_equal (&frac_rvt, &dconst1))
+ use_exp2 = true;
+ }
+ }
+ (if (!use_exp2)
+ (exps (mult (logs @0) @1))
+ /* As libmvec doesn't have a vectorized exp2, defer optimizing
+ this until after vectorization. */
+ (if (canonicalize_math_after_vectorization_p ())
+ (exps (mult (logs @0) @1))))))))
(for sqrts (SQRT)
cbrts (CBRT)
--- gcc/generic-match-head.c.jj 2018-01-03 10:19:55.454534005 +0100
+++ gcc/generic-match-head.c 2018-02-12 14:13:27.088784495 +0100
@@ -68,3 +68,12 @@ canonicalize_math_p ()
{
return true;
}
+
+/* Return true if math operations that are beneficial only after
+ vectorization should be canonicalized. */
+
+static inline bool
+canonicalize_math_after_vectorization_p ()
+{
+ return false;
+}
--- gcc/gimple-match-head.c.jj 2018-01-03 10:19:55.931534081 +0100
+++ gcc/gimple-match-head.c 2018-02-12 14:14:17.352781873 +0100
@@ -831,3 +831,12 @@ canonicalize_math_p ()
{
return !cfun || (cfun->curr_properties & PROP_gimple_opt_math) == 0;
}
+
+/* Return true if math operations that are beneficial only after
+ vectorization should be canonicalized. */
+
+static inline bool
+canonicalize_math_after_vectorization_p ()
+{
+ return !cfun || (cfun->curr_properties & PROP_gimple_lvec) != 0;
+}
--- gcc/omp-simd-clone.h.jj 2018-02-12 18:11:01.843931808 +0100
+++ gcc/omp-simd-clone.h 2018-02-12 18:12:13.901948041 +0100
@@ -0,0 +1,26 @@
+/* OMP constructs' SIMD clone supporting code.
+
+ Copyright (C) 2005-2018 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#ifndef GCC_OMP_SIMD_CLONE_H
+#define GCC_OMP_SIMD_CLONE_H
+
+extern void expand_simd_clones (struct cgraph_node *);
+
+#endif /* GCC_OMP_SIMD_CLONE_H */
--- gcc/omp-simd-clone.c.jj 2018-01-25 16:31:35.464138243 +0100
+++ gcc/omp-simd-clone.c 2018-02-12 18:10:48.214928742 +0100
@@ -50,6 +50,7 @@ along with GCC; see the file COPYING3.
#include "varasm.h"
#include "stringpool.h"
#include "attribs.h"
+#include "omp-simd-clone.h"
/* Return the number of elements in vector type VECTYPE, which is associated
with a SIMD clone. At present these always have a constant length. */
@@ -1568,7 +1569,7 @@ simd_clone_adjust (struct cgraph_node *n
/* If the function in NODE is tagged as an elemental SIMD function,
create the appropriate SIMD clones. */
-static void
+void
expand_simd_clones (struct cgraph_node *node)
{
tree attr = lookup_attribute ("omp declare simd",
--- gcc/tree-vect-patterns.c.jj 2018-01-23 14:48:52.783269685 +0100
+++ gcc/tree-vect-patterns.c 2018-02-12 18:15:49.730996661 +0100
@@ -41,6 +41,10 @@ along with GCC; see the file COPYING3.
#include "builtins.h"
#include "internal-fn.h"
#include "case-cfn-macros.h"
+#include "fold-const-call.h"
+#include "attribs.h"
+#include "cgraph.h"
+#include "omp-simd-clone.h"
/* Pattern recognition functions */
static gimple *vect_recog_widen_sum_pattern (vec<gimple *> *, tree *,
@@ -1049,7 +1053,7 @@ vect_recog_pow_pattern (vec<gimple *> *s
tree *type_out)
{
gimple *last_stmt = (*stmts)[0];
- tree base, exp = NULL;
+ tree base, exp;
gimple *stmt;
tree var;
@@ -1060,17 +1064,77 @@ vect_recog_pow_pattern (vec<gimple *> *s
{
CASE_CFN_POW:
CASE_CFN_POWI:
- base = gimple_call_arg (last_stmt, 0);
- exp = gimple_call_arg (last_stmt, 1);
- if (TREE_CODE (exp) != REAL_CST
- && TREE_CODE (exp) != INTEGER_CST)
- return NULL;
break;
default:
return NULL;
}
+ base = gimple_call_arg (last_stmt, 0);
+ exp = gimple_call_arg (last_stmt, 1);
+ if (TREE_CODE (exp) != REAL_CST
+ && TREE_CODE (exp) != INTEGER_CST)
+ {
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (base) == REAL_CST
+ && !gimple_call_internal_p (last_stmt))
+ {
+ combined_fn log_cfn;
+ built_in_function exp_bfn;
+ switch (DECL_FUNCTION_CODE (gimple_call_fndecl (last_stmt)))
+ {
+ case BUILT_IN_POW:
+ log_cfn = CFN_BUILT_IN_LOG;
+ exp_bfn = BUILT_IN_EXP;
+ break;
+ case BUILT_IN_POWF:
+ log_cfn = CFN_BUILT_IN_LOGF;
+ exp_bfn = BUILT_IN_EXPF;
+ break;
+ case BUILT_IN_POWL:
+ log_cfn = CFN_BUILT_IN_LOGL;
+ exp_bfn = BUILT_IN_EXPL;
+ break;
+ default:
+ return NULL;
+ }
+ tree logc = fold_const_call (log_cfn, TREE_TYPE (base), base);
+ tree exp_decl = builtin_decl_implicit (exp_bfn);
+ /* Optimize pow (C, x) as exp (log (C) * x). Normally match.pd
+ does that, but if C is a power of 2, we want to use
+ exp2 (log2 (C) * x) in the non-vectorized version, but for
+ vectorization we don't have vectorized exp2. */
+ if (logc
+ && TREE_CODE (logc) == REAL_CST
+ && exp_decl
+ && lookup_attribute ("omp declare simd",
+ DECL_ATTRIBUTES (exp_decl)))
+ {
+ cgraph_node *node = cgraph_node::get_create (exp_decl);
+ if (node->simd_clones == NULL)
+ {
+ if (node->definition)
+ return NULL;
+ expand_simd_clones (node);
+ if (node->simd_clones == NULL)
+ return NULL;
+ }
+ stmt_vec_info stmt_vinfo = vinfo_for_stmt (last_stmt);
+ tree def = vect_recog_temp_ssa_var (TREE_TYPE (base), NULL);
+ gimple *g = gimple_build_assign (def, MULT_EXPR, exp, logc);
+ new_pattern_def_seq (stmt_vinfo, g);
+ *type_in = TREE_TYPE (base);
+ *type_out = NULL_TREE;
+ tree res = vect_recog_temp_ssa_var (TREE_TYPE (base), NULL);
+ g = gimple_build_call (exp_decl, 1, def);
+ gimple_call_set_lhs (g, res);
+ return g;
+ }
+ }
+
+ return NULL;
+ }
+
/* We now have a pow or powi builtin function call with a constant
exponent. */
@@ -1744,8 +1808,8 @@ vect_recog_widen_shift_pattern (vec<gimp
/* Pattern supported. Create a stmt to be used to replace the pattern. */
var = vect_recog_temp_ssa_var (type, NULL);
- pattern_stmt =
- gimple_build_assign (var, WIDEN_LSHIFT_EXPR, oprnd0, oprnd1);
+ pattern_stmt
+ = gimple_build_assign (var, WIDEN_LSHIFT_EXPR, oprnd0, oprnd1);
if (wstmt)
{
stmt_vec_info stmt_vinfo = vinfo_for_stmt (last_stmt);
@@ -4439,10 +4503,6 @@ vect_pattern_recog_1 (vect_recog_func *r
}
else
{
- machine_mode vec_mode;
- enum insn_code icode;
- optab optab;
-
/* Check target support */
type_in = get_vectype_for_scalar_type (type_in);
if (!type_in)
@@ -4456,19 +4516,18 @@ vect_pattern_recog_1 (vect_recog_func *r
pattern_vectype = type_out;
if (is_gimple_assign (pattern_stmt))
- code = gimple_assign_rhs_code (pattern_stmt);
- else
- {
- gcc_assert (is_gimple_call (pattern_stmt));
- code = CALL_EXPR;
+ {
+ enum insn_code icode;
+ code = gimple_assign_rhs_code (pattern_stmt);
+ optab optab = optab_for_tree_code (code, type_in, optab_default);
+ machine_mode vec_mode = TYPE_MODE (type_in);
+ if (!optab
+ || (icode = optab_handler (optab, vec_mode)) == CODE_FOR_nothing
+ || (insn_data[icode].operand[0].mode != TYPE_MODE (type_out)))
+ return false;
}
-
- optab = optab_for_tree_code (code, type_in, optab_default);
- vec_mode = TYPE_MODE (type_in);
- if (!optab
- || (icode = optab_handler (optab, vec_mode)) == CODE_FOR_nothing
- || (insn_data[icode].operand[0].mode != TYPE_MODE (type_out)))
- return false;
+ else
+ gcc_assert (is_gimple_call (pattern_stmt));
}
/* Found a vectorizable pattern. */
--- gcc/testsuite/gcc.dg/pr84309.c.jj 2018-02-12 12:24:22.214522183 +0100
+++ gcc/testsuite/gcc.dg/pr84309.c 2018-02-12 12:24:22.214522183 +0100
@@ -0,0 +1,14 @@
+/* PR middle-end/84309 */
+/* { dg-do run { target c99_runtime } } */
+/* { dg-options "-O2 -ffast-math" } */
+
+int
+main ()
+{
+ unsigned long a = 1024;
+ unsigned long b = 16 * 1024;
+ unsigned long c = __builtin_pow (2, (__builtin_log2 (a) + __builtin_log2
(b)) / 2);
+ if (c != 4096)
+ __builtin_abort ();
+ return 0;
+}
--- gcc/testsuite/gcc.target/i386/pr84309.c.jj 2018-02-12 18:20:15.819056596
+0100
+++ gcc/testsuite/gcc.target/i386/pr84309.c 2018-02-12 18:21:00.462066648
+0100
@@ -0,0 +1,16 @@
+/* PR middle-end/84309 */
+/* { dg-do compile } */
+/* { dg-options "-Ofast -mavx" } */
+
+double pow (double, double) __attribute__((simd));
+double exp (double) __attribute__((simd));
+extern double a[1024], b[1024];
+
+void
+foo (void)
+{
+ for (int i = 0; i < 1024; ++i)
+ a[i] = pow (2.0, b[i]);
+}
+
+/* { dg-final { scan-assembler "_ZGVcN4v_exp" } } */
Jakub
