PR middle-end/8408

[Eric Botcazou <ebotcazou at libertysurf dot fr>]

This is a high-priority PR, regression on the mainline but not on the 
gcc-3_2-branch. The compiler ICEs during the ADDRESSOF purging pass in 
fixup_var_refs_1 on the following insn:

(insn 10 8 14 0 0x4014d294 (set (reg:CCZ 17 flags)
        (compare:CCZ (addressof:SI (reg/v:DF 61) 60 0x40176e70)
            (addressof:SI (reg/v:DF 59) 58 0x40176e00))) -1 (nil)
    (nil))

because the recognizer rejects the modified insn

(insn 10 8 14 0 0x4014d294 (set (reg:CCZ 17 flags)
        (compare:CCZ (addressof:SI (reg/v:DF 61) 60 0x40176e70)
            (reg/f:SI 62))) -1 (nil)
    (nil))

despite the following pattern in i386.md:

(define_insn "*cmpsi_1_insn"
  [(set (reg 17)
	(compare (match_operand:SI 0 "nonimmediate_operand" "rm,r")
		 (match_operand:SI 1 "general_operand" "ri,mr")))]
  "(GET_CODE (operands[0]) != MEM || GET_CODE (operands[1]) != MEM)
    && ix86_match_ccmode (insn, CCmode)"
  "cmp{l}\t{%1, %0|%0, %1}"
  [(set_attr "type" "icmp")
   (set_attr "mode" "SI")])

which should be matching (and is matching on the gcc-3_2-branch).


That's purely the recognizer's fault: because of some changes in the md file, 
the decision tree for cmpsi_1_insn on the mainline is very different from the 
one on the branch. More precisely, the nonimmediate_operand predicate for 
operand 0 is reached through the default case of a switch statement on the 
branch, which lets ADDRESSOF be accepted.

On the other hand, the decision tree for cmpsi_1_insn is merged with others on 
the mainline, so the nonimmediate_operand predicate is reached through 
explicit cases of a switch statement. Now the three only cases listed in 
genrecog.c for the nonimmediate_operand predicate are SUBREG, REG and MEM.

The proposed fix is to teach genrecog.c the ADDRESSOF code, based on what 
recog.c already knows about it. Bootstrapped/regtested (c,c++,objc,f77) on 
i586-redhat-linux-gnu. However, I experienced 1% increase in bootstrap time 
because of this patch.


2002-11-03  Eric Botcazou  <ebotcazou@libertysurf.fr>

	PR middle-end/8408
	* genrecog.c (preds): handle ADDRESSOF.
	(validate_pattern): mark it as lvalue.


-- 
Eric Botcazou
--- gcc/genrecog.c	Fri Nov  1 21:53:03 2002
+++ gcc/genrecog.c	Sun Nov  3 09:31:38 2002
@@ -187,22 +187,23 @@
   const RTX_CODE codes[NUM_RTX_CODE];
 } preds[] = {
   {"general_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
-		       LABEL_REF, SUBREG, REG, MEM}},
+		       LABEL_REF, SUBREG, REG, MEM, ADDRESSOF}},
 #ifdef PREDICATE_CODES
   PREDICATE_CODES
 #endif
   {"address_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
-		       LABEL_REF, SUBREG, REG, MEM, PLUS, MINUS, MULT}},
-  {"register_operand", {SUBREG, REG}},
-  {"pmode_register_operand", {SUBREG, REG}},
+		       LABEL_REF, SUBREG, REG, MEM, ADDRESSOF,
+		       PLUS, MINUS, MULT}},
+  {"register_operand", {SUBREG, REG, ADDRESSOF}},
+  {"pmode_register_operand", {SUBREG, REG, ADDRESSOF}},
   {"scratch_operand", {SCRATCH, REG}},
   {"immediate_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
 			 LABEL_REF}},
   {"const_int_operand", {CONST_INT}},
   {"const_double_operand", {CONST_INT, CONST_DOUBLE}},
-  {"nonimmediate_operand", {SUBREG, REG, MEM}},
+  {"nonimmediate_operand", {SUBREG, REG, MEM, ADDRESSOF}},
   {"nonmemory_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
-			 LABEL_REF, SUBREG, REG}},
+			 LABEL_REF, SUBREG, REG, ADDRESSOF}},
   {"push_operand", {MEM}},
   {"pop_operand", {MEM}},
   {"memory_operand", {SUBREG, MEM}},
@@ -211,7 +212,7 @@
 			   UNORDERED, ORDERED, UNEQ, UNGE, UNGT, UNLE,
 			   UNLT, LTGT}},
   {"mode_independent_operand", {CONST_INT, CONST_DOUBLE, CONST, SYMBOL_REF,
-				LABEL_REF, SUBREG, REG, MEM}}
+				LABEL_REF, SUBREG, REG, MEM, ADDRESSOF}}
 };
 
 #define NUM_KNOWN_PREDS ARRAY_SIZE (preds)
@@ -520,6 +521,7 @@
 		    if (c != REG
 			&& c != SUBREG
 			&& c != MEM
+			&& c != ADDRESSOF
 			&& c != CONCAT
 			&& c != PARALLEL
 			&& c != STRICT_LOW_PART)
/* PR middle-end/8408 */
/* Verify that the recognizer explicitly
   handles ADDRESSOF operands. */

void foo(void)
{
  double d1 = 3.14159, d2;
  if (&d2 == &d1)
     ;
}