From: Richard Sandiford <rdsandiford@googlemail.com>
To: gcc-patches@gcc.gnu.org
Subject: Move powi folds to match.pd
Date: Mon, 26 Oct 2015 09:50:00 -0000 [thread overview]
Message-ID: <87k2qavu3u.fsf@e105548-lin.cambridge.arm.com> (raw)
Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi.
OK to install?
Thanks,
Richard
gcc/
* builtins.c (fold_builtin_powi): Delete.
(fold_builtin_2): Handle constant powi arguments here.
* match.pd: Add rules previously handled by fold_builtin_powi.
gcc/testsuite/
* gcc.dg/builtins-52.c: Add -O to dg-options.
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 88c0576..3d39d43 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -156,7 +156,6 @@ static tree rewrite_call_expr (location_t, tree, int, tree, int, ...);
static bool validate_arg (const_tree, enum tree_code code);
static rtx expand_builtin_fabs (tree, rtx, rtx);
static rtx expand_builtin_signbit (tree, rtx);
-static tree fold_builtin_powi (location_t, tree, tree, tree, tree);
static tree fold_builtin_bitop (tree, tree);
static tree fold_builtin_strchr (location_t, tree, tree, tree);
static tree fold_builtin_memchr (location_t, tree, tree, tree, tree);
@@ -7517,52 +7516,6 @@ fold_const_builtin_pow (tree arg0, tree arg1, tree type)
return NULL_TREE;
}
-/* Fold a builtin function call to powi, powif, or powil with argument ARG.
- Return NULL_TREE if no simplification can be made. */
-static tree
-fold_builtin_powi (location_t loc, tree fndecl ATTRIBUTE_UNUSED,
- tree arg0, tree arg1, tree type)
-{
- if (!validate_arg (arg0, REAL_TYPE)
- || !validate_arg (arg1, INTEGER_TYPE))
- return NULL_TREE;
-
- /* Optimize pow(1.0,y) = 1.0. */
- if (real_onep (arg0))
- return omit_one_operand_loc (loc, type, build_real (type, dconst1), arg1);
-
- if (tree_fits_shwi_p (arg1))
- {
- HOST_WIDE_INT c = tree_to_shwi (arg1);
-
- /* Evaluate powi at compile-time. */
- if (TREE_CODE (arg0) == REAL_CST
- && !TREE_OVERFLOW (arg0))
- {
- REAL_VALUE_TYPE x;
- x = TREE_REAL_CST (arg0);
- real_powi (&x, TYPE_MODE (type), &x, c);
- return build_real (type, x);
- }
-
- /* Optimize pow(x,0) = 1.0. */
- if (c == 0)
- return omit_one_operand_loc (loc, type, build_real (type, dconst1),
- arg0);
-
- /* Optimize pow(x,1) = x. */
- if (c == 1)
- return arg0;
-
- /* Optimize pow(x,-1) = 1.0/x. */
- if (c == -1)
- return fold_build2_loc (loc, RDIV_EXPR, type,
- build_real (type, dconst1), arg0);
- }
-
- return NULL_TREE;
-}
-
/* A subroutine of fold_builtin to fold the various exponent
functions. Return NULL_TREE if no simplification can be made.
FUNC is the corresponding MPFR exponent function. */
@@ -9379,7 +9332,16 @@ fold_builtin_2 (location_t loc, tree fndecl, tree arg0, tree arg1)
return fold_const_builtin_pow (arg0, arg1, type);
CASE_FLT_FN (BUILT_IN_POWI):
- return fold_builtin_powi (loc, fndecl, arg0, arg1, type);
+ if (TREE_CODE (arg0) == REAL_CST
+ && !TREE_OVERFLOW (arg0)
+ && tree_fits_shwi_p (arg1))
+ {
+ HOST_WIDE_INT c = tree_to_shwi (arg1);
+ REAL_VALUE_TYPE x;
+ real_powi (&x, TYPE_MODE (type), TREE_REAL_CST_PTR (arg0), c);
+ return build_real (type, x);
+ }
+ break;
CASE_FLT_FN (BUILT_IN_COPYSIGN):
return fold_builtin_copysign (loc, arg0, arg1, type);
diff --git a/gcc/match.pd b/gcc/match.pd
index b681573..a8adffb 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -84,6 +84,7 @@ DEFINE_MATH_FN (LOG10)
DEFINE_MATH_FN (EXP10)
DEFINE_MATH_FN (POW)
DEFINE_MATH_FN (POW10)
+DEFINE_MATH_FN (POWI)
DEFINE_MATH_FN (SQRT)
DEFINE_MATH_FN (CBRT)
DEFINE_MATH_FN (SIN)
@@ -2821,6 +2822,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
real_equal (value, &tmp)))
(cbrts @0))))))
+/* powi(1,x) -> 1. */
+(simplify
+ (POWI real_onep@0 @1)
+ @0)
+
+(simplify
+ (POWI @0 INTEGER_CST@1)
+ (switch
+ /* powi(x,0) -> 1. */
+ (if (wi::eq_p (@1, 0))
+ { build_real (type, dconst1); })
+ /* powi(x,1) -> x. */
+ (if (wi::eq_p (@1, 1))
+ @0)
+ /* powi(x,-1) -> 1/x. */
+ (if (wi::eq_p (@1, -1))
+ (rdiv { build_real (type, dconst1); } @0))))
+
/* Narrowing of arithmetic and logical operations.
These are conceptually similar to the transformations performed for
diff --git a/gcc/testsuite/gcc.dg/builtins-52.c b/gcc/testsuite/gcc.dg/builtins-52.c
index 684fd66..1cff017 100644
--- a/gcc/testsuite/gcc.dg/builtins-52.c
+++ b/gcc/testsuite/gcc.dg/builtins-52.c
@@ -1,5 +1,5 @@
/* { dg-do link } */
-/* { dg-options "-ffast-math" } */
+/* { dg-options "-O -ffast-math" } */
extern void link_error(void);
next reply other threads:[~2015-10-26 9:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-26 9:50 Richard Sandiford [this message]
2015-10-26 10:15 ` Richard Biener
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87k2qavu3u.fsf@e105548-lin.cambridge.arm.com \
--to=rdsandiford@googlemail.com \
--cc=gcc-patches@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).