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

simplify-rtx.c (simplify_relational_operation_1): Implement some canonicalization transformations that attempt to simplify... 

* simplify-rtx.c (simplify_relational_operation_1): Implement some
	canonicalization transformations that attempt to simplify integer
	constant comparisons to become comparisons against zero.

From-SVN: r121544
This commit is contained in:
Roger Sayle 2007-02-03 16:22:09 +00:00 committed by Roger Sayle
parent 5041541e41
commit 3fa0cacdb5
2 changed files with 65 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2007-02-03 Roger Sayle <roger@eyesopen.com>
* simplify-rtx.c (simplify_relational_operation_1): Implement some
canonicalization transformations that attempt to simplify integer
constant comparisons to become comparisons against zero.
2007-02-03 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* builtins.c (fold_builtin_cabs): Fold cabs(x+xi) into

78
gcc/simplify-rtx.c
View File

@ -3595,28 +3595,68 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode,
{
enum rtx_code op0code = GET_CODE (op0);
if (GET_CODE (op1) == CONST_INT)
if (op1 == const0_rtx && COMPARISON_P (op0))
{
if (INTVAL (op1) == 0 && COMPARISON_P (op0))
/* If op0 is a comparison, extract the comparison arguments
from it. */
if (code == NE)
{
/* If op0 is a comparison, extract the comparison arguments
from it. */
if (code == NE)
{
if (GET_MODE (op0) == mode)
return simplify_rtx (op0);
else
return simplify_gen_relational (GET_CODE (op0), mode, VOIDmode,
XEXP (op0, 0), XEXP (op0, 1));
}
else if (code == EQ)
{
enum rtx_code new_code = reversed_comparison_code (op0, NULL_RTX);
if (new_code != UNKNOWN)
return simplify_gen_relational (new_code, mode, VOIDmode,
XEXP (op0, 0), XEXP (op0, 1));
}
if (GET_MODE (op0) == mode)
return simplify_rtx (op0);
else
return simplify_gen_relational (GET_CODE (op0), mode, VOIDmode,
XEXP (op0, 0), XEXP (op0, 1));
}
else if (code == EQ)
{
enum rtx_code new_code = reversed_comparison_code (op0, NULL_RTX);
if (new_code != UNKNOWN)
return simplify_gen_relational (new_code, mode, VOIDmode,
XEXP (op0, 0), XEXP (op0, 1));
}
}
if (op1 == const0_rtx)
{
/* Canonicalize (GTU x 0) as (NE x 0). */
if (code == GTU)
return simplify_gen_relational (NE, mode, cmp_mode, op0, op1);
/* Canonicalize (LEU x 0) as (EQ x 0). */
if (code == LEU)
return simplify_gen_relational (EQ, mode, cmp_mode, op0, op1);
}
else if (op1 == const1_rtx)
{
switch (code)
{
case GE:
/* Canonicalize (GE x 1) as (GT x 0). */
return simplify_gen_relational (GT, mode, cmp_mode,
op0, const0_rtx);
case GEU:
/* Canonicalize (GEU x 1) as (NE x 0). */
return simplify_gen_relational (NE, mode, cmp_mode,
op0, const0_rtx);
case LT:
/* Canonicalize (LT x 1) as (LE x 0). */
return simplify_gen_relational (LE, mode, cmp_mode,
op0, const0_rtx);
case LTU:
/* Canonicalize (LTU x 1) as (EQ x 0). */
return simplify_gen_relational (EQ, mode, cmp_mode,
op0, const0_rtx);
default:
break;
}
}
else if (op1 == constm1_rtx)
{
/* Canonicalize (LE x -1) as (LT x 0). */
if (code == LE)
return simplify_gen_relational (LT, mode, cmp_mode, op0, const0_rtx);
/* Canonicalize (GT x -1) as (GE x 0). */
if (code == GT)
return simplify_gen_relational (GE, mode, cmp_mode, op0, const0_rtx);
}
/* (eq/ne (plus x cst1) cst2) simplifies to (eq/ne x (cst2 - cst1)) */