OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

i386.c (ix86_expand_ashlsi3_const): New function to expand a left shift by an immediate constant as either an ashl...

Browse Source 
* config/i386/i386.c (ix86_expand_ashlsi3_const): New function to
	expand a left shift by an immediate constant as either an ashl or
	a sequence of additions.
	(ix86_split_ashldi): Use new ix86_expand_ashlsi3_const function
	instead of calling gen_ashlsi3 with a constant directly.

From-SVN: r87271
This commit is contained in:
Roger Sayle 2004-09-10 02:32:19 +00:00 committed by Roger Sayle
parent 903a5059b6
commit 1b83d20963
2 changed files with 30 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2004-09-09 Roger Sayle <roger@eyesopen.com>
* config/i386/i386.c (ix86_expand_ashlsi3_const): New function to
expand a left shift by an immediate constant as either an ashl or
a sequence of additions.
(ix86_split_ashldi): Use new ix86_expand_ashlsi3_const function
instead of calling gen_ashlsi3 with a constant directly.
2004-09-09 Roger Sayle <roger@eyesopen.com>
* config/i386/i386.c (ix86_split_long_move): When optimizing for

24
gcc/config/i386/i386.c
View File

@ -9973,6 +9973,26 @@ ix86_split_long_move (rtx operands[])
return;
}
/* Helper function of ix86_split_ashldi used to generate an SImode
left shift by a constant, either using a single shift or
a sequence of add instructions. */
static void
ix86_expand_ashlsi3_const (rtx operand, int count)
{
if (count == 1)
emit_insn (gen_addsi3 (operand, operand, operand));
else if (!optimize_size
&& count * ix86_cost->add <= ix86_cost->shift_const)
{
int i;
for (i=0; i<count; i++)
emit_insn (gen_addsi3 (operand, operand, operand));
}
else
emit_insn (gen_ashlsi3 (operand, operand, GEN_INT (count)));
}
void
ix86_split_ashldi (rtx *operands, rtx scratch)
{
@ -9990,14 +10010,14 @@ ix86_split_ashldi (rtx *operands, rtx scratch)
emit_move_insn (low[0], const0_rtx);
if (count > 32)
emit_insn (gen_ashlsi3 (high[0], high[0], GEN_INT (count - 32)));
ix86_expand_ashlsi3_const (high[0], count - 32);
}
else
{
if (!rtx_equal_p (operands[0], operands[1]))
emit_move_insn (operands[0], operands[1]);
emit_insn (gen_x86_shld_1 (high[0], low[0], GEN_INT (count)));
emit_insn (gen_ashlsi3 (low[0], low[0], GEN_INT (count)));
ix86_expand_ashlsi3_const (low[0], count);
}
}
else