diff options
| author | Nathan Sidwell <nathan@codesourcery.com> | 2002-12-23 14:43:28 +0000 |
|---|---|---|
| committer | Nathan Sidwell <nathan@gcc.gnu.org> | 2002-12-23 14:43:28 +0000 |
| commit | 0c685f1256349ca34726d19826dad68f3559a6e1 (patch) | |
| tree | 31685ad42eeb50810729dd451ba7b19f425a95a3 /gcc | |
| parent | 1df7e439e15df663a524df0bbc3aa59617383db0 (diff) | |
| download | gcc-0c685f1256349ca34726d19826dad68f3559a6e1.zip gcc-0c685f1256349ca34726d19826dad68f3559a6e1.tar.gz gcc-0c685f1256349ca34726d19826dad68f3559a6e1.tar.bz2 | |
tree.c (save_expr): Allow either side of a dyadic operand to be constant.
* tree.c (save_expr): Allow either side of a dyadic operand to be
constant.
* doc/portability.texi (portability): Update portability goals.
From-SVN: r60435
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/doc/portability.texi | 11 | ||||
| -rw-r--r-- | gcc/tree.c | 26 |
3 files changed, 32 insertions, 12 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 114be45..ae22fbc 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2002-12-22 Nathan Sidwell <nathan@codesourcery.com> + + * tree.c (save_expr): Allow either side of a dyadic operand to be + constant. + + * doc/portability.texi (portability): Update portability goals. + 2002-12-23 Kazu Hirata <kazu@cs.umass.edu> * config/h8300/h8300.c (output_a_shift): Remove unused code. diff --git a/gcc/doc/portability.texi b/gcc/doc/portability.texi index c3d8e39..b05698d 100644 --- a/gcc/doc/portability.texi +++ b/gcc/doc/portability.texi @@ -1,5 +1,5 @@ @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, -@c 1999, 2000, 2001 Free Software Foundation, Inc. +@c 1999, 2000, 2001, 2002 Free Software Foundation, Inc. @c This is part of the GCC manual. @c For copying conditions, see the file gcc.texi. @@ -8,10 +8,11 @@ @cindex portability @cindex GCC and portability -The main goal of GCC was to make a good, fast compiler for machines in -the class that the GNU system aims to run on: 32-bit machines that address -8-bit bytes and have several general registers. Elegance, theoretical -power and simplicity are only secondary. +GCC itself aims to be portable to any machine where @code{int} is at least +a 32-bit type. It aims to target machines with a flat (non-segmented) byte +addressed data address space (the code address space can be separate). +Target ABIs may have 8, 16, 32 or 64-bit @code{int} type. @code{char} +can be wider than 8 bits. GCC gets most of the information about the target machine from a machine description which gives an algebraic formula for each of the machine's @@ -1363,12 +1363,23 @@ save_expr (expr) a constant, it will be more efficient to not make another SAVE_EXPR since it will allow better simplification and GCSE will be able to merge the computations if they actualy occur. */ - for (inner = t; - (TREE_CODE_CLASS (TREE_CODE (inner)) == '1' - || (TREE_CODE_CLASS (TREE_CODE (inner)) == '2' - && TREE_CONSTANT (TREE_OPERAND (inner, 1)))); - inner = TREE_OPERAND (inner, 0)) - ; + inner = t; + while (1) + { + if (TREE_CODE_CLASS (TREE_CODE (inner)) == '1') + inner = TREE_OPERAND (inner, 0); + else if (TREE_CODE_CLASS (TREE_CODE (inner)) == '2') + { + if (TREE_CONSTANT (TREE_OPERAND (inner, 1))) + inner = TREE_OPERAND (inner, 0); + else if (TREE_CONSTANT (TREE_OPERAND (inner, 0))) + inner = TREE_OPERAND (inner, 1); + else + break; + } + else + break; + } /* If the tree evaluates to a constant, then we don't want to hide that fact (i.e. this allows further folding, and direct checks for constants). @@ -1377,7 +1388,8 @@ save_expr (expr) literal node. */ if (TREE_CONSTANT (inner) || (TREE_READONLY (inner) && ! TREE_SIDE_EFFECTS (inner)) - || TREE_CODE (inner) == SAVE_EXPR || TREE_CODE (inner) == ERROR_MARK) + || TREE_CODE (inner) == SAVE_EXPR + || TREE_CODE (inner) == ERROR_MARK) return t; /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since |