* combine.c (simplify_comparison <AND>): Check

	TRULY_NOOP_TRUNCATION before start using a subreg.

	* config/mips/mips.md (*branch_zero<mode>,
	*branch_zero<mode>_inverted, *branch_equality<mode>,
	*branch_equality<mode>_inverted, *branch_equality<mode>_mips16):
	Remove mode check from comparisons.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@110358 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ec8ba0f..b9900bf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2006-01-28  Adam Nemet  <anemet@caviumnetworks.com>
+
+       * combine.c (simplify_comparison <AND>): Check
+       TRULY_NOOP_TRUNCATION before start using a subreg.
+       
+       * config/mips/mips.md (*branch_zero<mode>, 
+       *branch_zero<mode>_inverted, *branch_equality<mode>, 
+       *branch_equality<mode>_inverted, *branch_equality<mode>_mips16): 
+       Remove mode check from comparisons. 
+
 2006-01-28  Kenneth Zadeck <zadeck@naturalbridge.com>
 
        * config/mips/mips-protos.h (mips_set_live_on_entry): Deleted.

diff --git a/gcc/combine.c b/gcc/combine.c
index 2c90be5..ee8d98d 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -10295,14 +10295,27 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1)
          /* If this AND operation is really a ZERO_EXTEND from a narrower
             mode, the constant fits within that mode, and this is either an
             equality or unsigned comparison, try to do this comparison in
-            the narrower mode.  */
+            the narrower mode.
+
+            Note that in:
+
+            (ne:DI (and:DI (reg:DI 4) (const_int 0xffffffff)) (const_int 0))
+            -> (ne:DI (reg:SI 4) (const_int 0))
+
+            unless TRULY_NOOP_TRUNCATION allows it or the register is
+            known to hold a value of the required mode the
+            transformation is invalid.  */
          if ((equality_comparison_p || unsigned_comparison_p)
              && GET_CODE (XEXP (op0, 1)) == CONST_INT
              && (i = exact_log2 ((INTVAL (XEXP (op0, 1))
                                   & GET_MODE_MASK (mode))
                                  + 1)) >= 0
              && const_op >> i == 0
-             && (tmode = mode_for_size (i, MODE_INT, 1)) != BLKmode)
+             && (tmode = mode_for_size (i, MODE_INT, 1)) != BLKmode
+             && (TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (tmode),
+                                        GET_MODE_BITSIZE (GET_MODE (op0)))
+                 || (REG_P (XEXP (op0, 0))
+                     && reg_truncated_to_mode (tmode, XEXP (op0, 0)))))
            {
              op0 = gen_lowpart (tmode, XEXP (op0, 0));
              continue;

diff --git a/gcc/config/mips/mips.md b/gcc/config/mips/mips.md
index af8f709..3d55857 100644 (file)
--- a/gcc/config/mips/mips.md
+++ b/gcc/config/mips/mips.md
@@ -4316,9 +4316,9 @@
 (define_insn "*branch_zero<mode>"
   [(set (pc)
        (if_then_else
-        (match_operator:GPR 0 "comparison_operator"
-                            [(match_operand:GPR 2 "register_operand" "d")
-                             (const_int 0)])
+        (match_operator 0 "comparison_operator"
+                        [(match_operand:GPR 2 "register_operand" "d")
+                         (const_int 0)])
         (label_ref (match_operand 1 "" ""))
         (pc)))]
   "!TARGET_MIPS16"
@@ -4336,9 +4336,9 @@
 (define_insn "*branch_zero<mode>_inverted"
   [(set (pc)
        (if_then_else
-        (match_operator:GPR 0 "comparison_operator"
-                            [(match_operand:GPR 2 "register_operand" "d")
-                             (const_int 0)])
+        (match_operator 0 "comparison_operator"
+                        [(match_operand:GPR 2 "register_operand" "d")
+                         (const_int 0)])
         (pc)
         (label_ref (match_operand 1 "" ""))))]
   "!TARGET_MIPS16"
@@ -4358,9 +4358,9 @@
 (define_insn "*branch_equality<mode>"
   [(set (pc)
        (if_then_else
-        (match_operator:GPR 0 "equality_operator"
-                            [(match_operand:GPR 2 "register_operand" "d")
-                             (match_operand:GPR 3 "register_operand" "d")])
+        (match_operator 0 "equality_operator"
+                        [(match_operand:GPR 2 "register_operand" "d")
+                         (match_operand:GPR 3 "register_operand" "d")])
         (label_ref (match_operand 1 "" ""))
         (pc)))]
   "!TARGET_MIPS16"
@@ -4378,9 +4378,9 @@
 (define_insn "*branch_equality<mode>_inverted"
   [(set (pc)
        (if_then_else
-        (match_operator:GPR 0 "equality_operator"
-                            [(match_operand:GPR 2 "register_operand" "d")
-                             (match_operand:GPR 3 "register_operand" "d")])
+        (match_operator 0 "equality_operator"
+                        [(match_operand:GPR 2 "register_operand" "d")
+                         (match_operand:GPR 3 "register_operand" "d")])
         (pc)
         (label_ref (match_operand 1 "" ""))))]
   "!TARGET_MIPS16"
@@ -4400,9 +4400,9 @@
 (define_insn "*branch_equality<mode>_mips16"
   [(set (pc)
        (if_then_else
-        (match_operator:GPR 0 "equality_operator"
-                            [(match_operand:GPR 1 "register_operand" "d,t")
-                             (const_int 0)])
+        (match_operator 0 "equality_operator"
+                        [(match_operand:GPR 1 "register_operand" "d,t")
+                         (const_int 0)])
         (match_operand 2 "pc_or_label_operand" "")
         (match_operand 3 "pc_or_label_operand" "")))]
   "TARGET_MIPS16"