re PR target/25554 (unrecognizable insn on x86_64 with -O2 -ftracer (…

re PR target/25554 (unrecognizable insn on x86_64 with -O2 -ftracer ( -fno-tree-dominator-opts on the mainline))

	PR target/25554
	* config/i386/i386.md (testqi_ext_3): Ensure len is positive
	and pos non-negative and pos + len <= 32.
	(testqi_ext_3_rex64): Ensure len is positive and pos non-negative,
	drop pos + len < HOST_BITS_PER_WIDE_INT test.
	(testqi_ext_3* splitter): Handle pos + len == HOST_BITS_PER_WIDE_INT.

	* gcc.c-torture/compile/20051228-1.c: New test.

From-SVN: r109317

gcc/ChangeLog

 2006-01-04  Jakub Jelinek  <jakub@redhat.com>
 
+	PR target/25554
+	* config/i386/i386.md (testqi_ext_3): Ensure len is positive
+	and pos non-negative and pos + len <= 32.
+	(testqi_ext_3_rex64): Ensure len is positive and pos non-negative,
+	drop pos + len < HOST_BITS_PER_WIDE_INT test.
+	(testqi_ext_3* splitter): Handle pos + len == HOST_BITS_PER_WIDE_INT.
+
 	PR c/25559
 	* c-common.c (handle_vector_size_attribute): Reject zero vector size
 	as well as sizes not multiple of component size.

gcc/config/i386/i386.md

@@ -7865,6 +7865,9 @@
 		   (match_operand:SI 2 "const_int_operand" ""))
 		 (const_int 0)))]
   "ix86_match_ccmode (insn, CCNOmode)
+   && INTVAL (operands[1]) > 0
+   && INTVAL (operands[2]) >= 0
+   && INTVAL (operands[1]) + INTVAL (operands[2]) <= 32
    && (GET_MODE (operands[0]) == SImode
        || (TARGET_64BIT && GET_MODE (operands[0]) == DImode)
        || GET_MODE (operands[0]) == HImode
@@ -7880,8 +7883,8 @@
 		 (const_int 0)))]
   "TARGET_64BIT
    && ix86_match_ccmode (insn, CCNOmode)
-   /* The code below cannot deal with constants outside HOST_WIDE_INT.  */
-   && INTVAL (operands[1]) + INTVAL (operands[2]) < HOST_BITS_PER_WIDE_INT
+   && INTVAL (operands[1]) > 0
+   && INTVAL (operands[2]) >= 0
    /* Ensure that resulting mask is zero or sign extended operand.  */
    && (INTVAL (operands[1]) + INTVAL (operands[2]) <= 32
        || (INTVAL (operands[1]) + INTVAL (operands[2]) == 64
@@ -7936,8 +7939,11 @@
       val = gen_lowpart (QImode, val);
     }
 
-  mask  = ((HOST_WIDE_INT)1 << (pos + len)) - 1;
-  mask &= ~(((HOST_WIDE_INT)1 << pos) - 1);
+  if (len == HOST_BITS_PER_WIDE_INT)
+    mask = -1;
+  else
+    mask = ((HOST_WIDE_INT)1 << len) - 1;
+  mask <<= pos;
 
   operands[2] = gen_rtx_AND (mode, val, gen_int_mode (mask, mode));
 })

gcc/testsuite/gcc.c-torture/compile/20051228-1.c

+/* PR target/25554 */
+/* Bitwise shift with negative shift count has undefined behavior,
+   but we shouldn't ICE on it.  */
+
+void
+foo (long x)
+{
+  if (((x >> -2) & 1) != 0)
+    bar ();
+}