From 81098a4adbab4efb5666ae39f8e8a1acd699aefa Mon Sep 17 00:00:00 2001 From: rth Date: Wed, 24 Oct 2001 22:11:40 +0000 Subject: [PATCH] * stmt.c (expand_end_case): Index jumptables from zero for suitably small values of minval. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@46478 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 5 +++++ gcc/stmt.c | 13 ++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index f704e4a..1dfc939 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2001-10-24 Roger Sayle + + * stmt.c (expand_end_case): Index jumptables from zero for + suitably small values of minval. + 2001-10-24 Jakub Jelinek * stor-layout.c (place_union_field): If any field was aligned with diff --git a/gcc/stmt.c b/gcc/stmt.c index 4943397..76fa439 100644 --- a/gcc/stmt.c +++ b/gcc/stmt.c @@ -5534,6 +5534,17 @@ expand_end_case (orig_index) table_label, default_label)) { index_type = thiscase->data.case_stmt.nominal_type; + + /* Index jumptables from zero for suitable values of + minval to avoid a subtraction. */ + if (! optimize_size + && compare_tree_int (minval, 0) > 0 + && compare_tree_int (minval, 3) < 0) + { + minval = integer_zero_node; + range = maxval; + } + if (! try_tablejump (index_type, index_expr, minval, range, table_label, default_label)) abort (); @@ -5541,7 +5552,7 @@ expand_end_case (orig_index) /* Get table of labels to jump to, in order of case index. */ - ncases = TREE_INT_CST_LOW (range) + 1; + ncases = tree_low_cst (range, 0) + 1; labelvec = (rtx *) alloca (ncases * sizeof (rtx)); memset ((char *) labelvec, 0, ncases * sizeof (rtx)); -- 2.7.4