simplify-rtx.c (simplify_relational_operation_1): Simplify (ne:SI…

simplify-rtx.c (simplify_relational_operation_1): Simplify (ne:SI (zero_extract:SI FOO (const_int 1) BAR) (const_int 0)) into...


	* simplify-rtx.c (simplify_relational_operation_1): Simplify
	(ne:SI (zero_extract:SI FOO (const_int 1) BAR) (const_int 0))
	into just (zero_extract:SI FOO (const_int 1) BAR).

Co-Authored-By: Andrew Pinski <pinskia@physics.uc.edu>
Co-Authored-By: Paolo Bonzini <paolo.bonzini@lu.unisi.ch>

From-SVN: r94684

gcc/ChangeLog

+2005-02-06  Roger Sayle  <roger@eyesopen.com>
+	    Andrew Pinski  <pinskia@physics.uc.edu>
+	    Paolo Bonzini  <paolo.bonzini@lu.unisi.ch>
+
+	* simplify-rtx.c (simplify_relational_operation_1): Simplify
+	(ne:SI (zero_extract:SI FOO (const_int 1) BAR) (const_int 0))
+	into just (zero_extract:SI FOO (const_int 1) BAR).
+
 2005-02-06  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* doc/cpp.texi: Include gcc-common.texi.  Don't define gcctabopt

gcc/simplify-rtx.c

@@ -2880,6 +2880,18 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode,
       return simplify_gen_relational (code, mode, cmp_mode, x, c);
     }
 
+  /* (ne:SI (zero_extract:SI FOO (const_int 1) BAR) (const_int 0))) is
+     the same as (zero_extract:SI FOO (const_int 1) BAR).  */
+  if (code == NE
+      && op1 == const0_rtx
+      && GET_MODE_CLASS (mode) == MODE_INT
+      && cmp_mode != VOIDmode
+      && nonzero_bits (op0, cmp_mode) == 1
+      && STORE_FLAG_VALUE == 1)
+    return GET_MODE_SIZE (mode) > GET_MODE_SIZE (cmp_mode)
+	   ? simplify_gen_unary (ZERO_EXTEND, mode, op0, cmp_mode)
+	   : gen_lowpart (mode, op0);
+
   return NULL_RTX;
 }