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| author | Jim Wilson <wilson@cygnus.com> | 1997-10-26 20:33:27 +0000 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1997-10-26 13:33:27 -0700 |
| commit | 7581a30fe2ff49b4e1bf432f6cc5f27efce7ea7e (patch) | |
| tree | 88ec44b5f1866a21232e71ea7a665d891e885af5 | |
| parent | edaa4ee0621bfd1747c56e0f77edc72c29510bfe (diff) | |
| download | gcc-7581a30fe2ff49b4e1bf432f6cc5f27efce7ea7e.zip gcc-7581a30fe2ff49b4e1bf432f6cc5f27efce7ea7e.tar.gz gcc-7581a30fe2ff49b4e1bf432f6cc5f27efce7ea7e.tar.bz2 | |
expr.c (expand_expr, [...]): Optimize a reference to an element in a constant string.
* expr.c (expand_expr, case INDIRECT_REF): Optimize a reference
to an element in a constant string.
From-SVN: r16195
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/expr.c | 12 |
2 files changed, 17 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8800542..5cb05f8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Sun Oct 26 13:31:47 1997 Jim Wilson (wilson@cygnus.com) + + * expr.c (expand_expr, case INDIRECT_REF): Optimize a reference + to an element in a constant string. + Sun Oct 26 11:41:49 1997 Jason Merrill <jason@yorick.cygnus.com> * dwarf2out.c (output_call_frame_info): The CIE pointer is now a 32 @@ -5406,6 +5406,18 @@ expand_expr (exp, target, tmode, modifier) { tree exp1 = TREE_OPERAND (exp, 0); tree exp2; + tree index; + tree string = string_constant (exp1, &index); + int i; + + if (string + && TREE_CODE (string) == STRING_CST + && TREE_CODE (index) == INTEGER_CST + && !TREE_INT_CST_HIGH (index) + && (i = TREE_INT_CST_LOW (index)) < TREE_STRING_LENGTH (string) + && GET_MODE_CLASS (mode) == MODE_INT + && GET_MODE_SIZE (mode) == 1) + return GEN_INT (TREE_STRING_POINTER (string)[i]); op0 = expand_expr (exp1, NULL_RTX, VOIDmode, EXPAND_SUM); op0 = memory_address (mode, op0); |