From b412f568222269c5beb2f77dd95b59543f017c63 Mon Sep 17 00:00:00 2001
From: neil <neil@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 28 May 2002 05:44:06 +0000
Subject: [PATCH] * cppexp.c (interpret_number): Optimize for
single-digit and less-than-half-precision cases. (num_trim,
num_positive, num_div_op): Cast constants.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@53943 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 6 +++++
gcc/cppexp.c | 72 ++++++++++++++++++++++++++++++++++++---------------
2 files changed, 57 insertions(+), 21 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e820f949d4b9..32c1c57d83cd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2002-05-28 Neil Booth <neil@daikokuya.demon.co.uk>
+
+ * cppexp.c (interpret_number): Optimize for single-digit
+ and less-than-half-precision cases.
+ (num_trim, num_positive, num_div_op): Cast constants.
+
2002-05-27 Roger Sayle <roger@eyesopen.com>
* c-common.c: Add support for __attribute__((nothrow)) to specify
diff --git a/gcc/cppexp.c b/gcc/cppexp.c
index 53411fe2ac65..c76e330fc28a 100644
--- a/gcc/cppexp.c
+++ b/gcc/cppexp.c
@@ -176,21 +176,31 @@ interpret_number (pfile, tok)
const cpp_token *tok;
{
cpp_num result;
- const uchar *start = tok->val.str.text;
- const uchar *end = start + tok->val.str.len;
- const uchar *p = start;
+ cpp_num_part max;
+ const uchar *p = tok->val.str.text;
+ const uchar *end;
const struct suffix *sufftab;
- size_t precision = CPP_OPTION (pfile, precision);
- unsigned int i, nsuff, base = 10, c = 0, largest_digit = 0;
- bool overflow = false;
+ size_t precision;
+ unsigned int i, nsuff, base, c;
+ bool overflow, big_digit;
- result.low = result.high = 0;
+ result.low = 0;
+ result.high = 0;
result.unsignedp = 0;
result.overflow = 0;
+ /* Common case of a single digit. */
+ end = p + tok->val.str.len;
+ if (tok->val.str.len == 1 && (unsigned int) (p[0] - '0') <= 9)
+ {
+ result.low = p[0] - '0';
+ return result;
+ }
+
+ base = 10;
if (p[0] == '0')
{
- if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X'))
+ if (end - p >= 3 && (p[1] == 'x' || p[1] == 'X'))
{
p += 2;
base = 16;
@@ -202,6 +212,18 @@ interpret_number (pfile, tok)
}
}
+ c = 0;
+ overflow = big_digit = false;
+ precision = CPP_OPTION (pfile, precision);
+
+ /* We can add a digit to numbers less than this without needing
+ double integers. 9 is the maximum digit for octal and decimal;
+ for hex it is annihilated by the division anyway. */
+ max = ~(cpp_num_part) 0;
+ if (precision < PART_PRECISION)
+ max >>= PART_PRECISION - precision;
+ max = (max - 9) / base + 1;
+
for(; p < end; p++)
{
c = *p;
@@ -211,10 +233,18 @@ interpret_number (pfile, tok)
else
break;
- result = append_digit (result, c, base, precision);
- overflow |= result.overflow;
- if (largest_digit < c)
- largest_digit = c;
+ if (c >= base)
+ big_digit = true;
+
+ /* Strict inequality for when max is set to zero. */
+ if (result.low < max)
+ result.low = result.low * base + c;
+ else
+ {
+ result = append_digit (result, c, base, precision);
+ overflow |= result.overflow;
+ max = 0;
+ }
}
if (p < end)
@@ -256,7 +286,7 @@ interpret_number (pfile, tok)
"too many 'l' suffixes in integer constant");
}
- if (base <= largest_digit)
+ if (big_digit)
cpp_error (pfile, DL_PEDWARN,
"integer constant contains digits beyond the radix");
@@ -787,12 +817,12 @@ num_trim (num, precision)
{
precision -= PART_PRECISION;
if (precision < PART_PRECISION)
- num.high &= (1UL << precision) - 1;
+ num.high &= ((cpp_num_part) 1 << precision) - 1;
}
else
{
if (precision < PART_PRECISION)
- num.low &= (1UL << precision) - 1;
+ num.low &= ((cpp_num_part) 1 << precision) - 1;
num.high = 0;
}
@@ -808,10 +838,10 @@ num_positive (num, precision)
if (precision > PART_PRECISION)
{
precision -= PART_PRECISION;
- return (num.high & (1UL << (precision - 1))) == 0;
+ return (num.high & (cpp_num_part) 1 << (precision - 1)) == 0;
}
- return (num.low & (1UL << (precision - 1))) == 0;
+ return (num.low & (cpp_num_part) 1 << (precision - 1)) == 0;
}
/* Returns the negative of NUM. */
@@ -1245,7 +1275,7 @@ num_div_op (pfile, lhs, rhs, op)
if (rhs.high)
{
i = precision - 1;
- mask = 1UL << (i - PART_PRECISION);
+ mask = (cpp_num_part) 1 << (i - PART_PRECISION);
for (; ; i--, mask >>= 1)
if (rhs.high & mask)
break;
@@ -1256,7 +1286,7 @@ num_div_op (pfile, lhs, rhs, op)
i = precision - PART_PRECISION - 1;
else
i = precision - 1;
- mask = 1UL << i;
+ mask = (cpp_num_part) 1 << i;
for (; ; i--, mask >>= 1)
if (rhs.low & mask)
break;
@@ -1284,9 +1314,9 @@ num_div_op (pfile, lhs, rhs, op)
{
lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
if (i >= PART_PRECISION)
- result.high |= 1UL << (i - PART_PRECISION);
+ result.high |= (cpp_num_part) 1 << (i - PART_PRECISION);
else
- result.low |= 1UL << i;
+ result.low |= (cpp_num_part) 1 << i;
}
if (i-- == 0)
break;
--
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