2004-10-09 Roger Sayle <roger@eyesopen.com>

	PR rtl-optimization/17853
	* simplify-rtx.c (simplify_relational_operation): Correct comment.
	Reorganize handling of comparison operations with floating point
	results (always return 0.0 even without FLOAT_STORE_FLAG_VALUE).
	Likewise, introduce support for comparison operations with vector
	result types, introducing a new VECTOR_STORE_FLAG_VALUE target macro.

	* doc/rtl.texi: Document new VECTOR_STORE_FLAG_VALUE target macro.
	* doc/tm.texi: Likewise.

2004-10-09  Stuart Hastings  <stuart@apple.com>
	    Roger Sayle  <roger@eyesopen.com>

	PR rtl-optimization/17853
	* gcc.dg/i386-mmx-5.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@88826 138bc75d-0d04-0410-961f-82ee72b054a4

6 files changed, 88 insertions, 11 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e1386742412..1107817bc82 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2004-10-09  Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/17853
+	* simplify-rtx.c (simplify_relational_operation): Correct comment.
+	Reorganize handling of comparison operations with floating point
+	results (always return 0.0 even without FLOAT_STORE_FLAG_VALUE).
+	Likewise, introduce support for comparison operations with vector
+	result types, introducing a new VECTOR_STORE_FLAG_VALUE target macro.
+
+	* doc/rtl.texi: Document new VECTOR_STORE_FLAG_VALUE target macro.
+	* doc/tm.texi: Likewise.
+
 2004-10-09  Steven Bosscher  <stevenb@suse.de>
 
 	* regs.h (struct reg_info_def): Remove the last_node_uid and
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 113dc147e79..3a72c167341 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -2028,10 +2028,13 @@ Comparison operators test a relation on two operands and are considered
 to represent a machine-dependent nonzero value described by, but not
 necessarily equal to, @code{STORE_FLAG_VALUE} (@pxref{Misc})
 if the relation holds, or zero if it does not, for comparison operators
-whose results have a `MODE_INT' mode, and
+whose results have a `MODE_INT' mode,
 @code{FLOAT_STORE_FLAG_VALUE} (@pxref{Misc}) if the relation holds, or
 zero if it does not, for comparison operators that return floating-point
-values.  The mode of the comparison operation is independent of the mode
+values, and a vector of either @code{VECTOR_STORE_FLAG_VALUE} (@pxref{Misc})
+if the relation holds, or of zeros if it does not, for comparison operators
+that return vector results.
+The mode of the comparison operation is independent of the mode
 of the data being compared.  If the comparison operation is being tested
 (e.g., the first operand of an @code{if_then_else}), the mode must be
 @code{VOIDmode}.
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 71c72c84603..69f60c14335 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -8920,11 +8920,23 @@ instructions, or if the value generated by these instructions is 1.
 @defmac FLOAT_STORE_FLAG_VALUE (@var{mode})
 A C expression that gives a nonzero @code{REAL_VALUE_TYPE} value that is
 returned when comparison operators with floating-point results are true.
-Define this macro on machine that have comparison operations that return
+Define this macro on machines that have comparison operations that return
 floating-point values.  If there are no such operations, do not define
 this macro.
 @end defmac
 
+@defmac VECTOR_STORE_FLAG_VALUE (@var{mode})
+A C expression that gives a rtx representing the non-zero true element
+for vector comparisons.  The returned rtx should be valid for the inner
+mode of @var{mode} which is guaranteed to be a vector mode.  Define
+this macro on machines that have vector comparison operations that
+return a vector result.  If there are no such operations, do not define
+this macro.  Typically, this macro is defined as @code{const1_rtx} or
+@code{constm1_rtx}.  This macro may return @code{NULL_RTX} to prevent
+the compiler optimizing such vector comparison operations for the
+given mode.
+@end defmac
+
 @defmac CLZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
 @defmacx CTZ_DEFINED_VALUE_AT_ZERO (@var{mode}, @var{value})
 A C expression that evaluates to true if the architecture defines a value
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index eec2a5816a3..7236bbfc064 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -2679,7 +2679,7 @@ simplify_plus_minus (enum rtx_code code, enum machine_mode mode, rtx op0,
 
 /* Like simplify_binary_operation except used for relational operators.
    MODE is the mode of the result. If MODE is VOIDmode, both operands must
-   also be VOIDmode.
+   not also be VOIDmode.
 
    CMP_MODE specifies in which mode the comparison is done in, so it is
    the mode of the operands.  If CMP_MODE is VOIDmode, it is taken from
@@ -2699,19 +2699,45 @@ simplify_relational_operation (enum rtx_code code, enum machine_mode mode,
   tem = simplify_const_relational_operation (code, cmp_mode, op0, op1);
   if (tem)
     {
-#ifdef FLOAT_STORE_FLAG_VALUE
       if (GET_MODE_CLASS (mode) == MODE_FLOAT)
 	{
           if (tem == const0_rtx)
             return CONST0_RTX (mode);
-          else if (GET_MODE_CLASS (mode) == MODE_FLOAT)
-	    {
-	      REAL_VALUE_TYPE val;
-	      val = FLOAT_STORE_FLAG_VALUE (mode);
-	      return CONST_DOUBLE_FROM_REAL_VALUE (val, mode);
-	    }
+#ifdef FLOAT_STORE_FLAG_VALUE
+	  {
+	    REAL_VALUE_TYPE val;
+	    val = FLOAT_STORE_FLAG_VALUE (mode);
+	    return CONST_DOUBLE_FROM_REAL_VALUE (val, mode);
+	  }
+#else
+	  return NULL_RTX;
+#endif 
 	}
+      if (VECTOR_MODE_P (mode))
+	{
+	  if (tem == const0_rtx)
+	    return CONST0_RTX (mode);
+#ifdef VECTOR_STORE_FLAG_VALUE
+	  {
+	    int i, units;
+	    rtvec c;
+
+	    rtx val = VECTOR_STORE_FLAG_VALUE (mode);
+	    if (val == NULL_RTX)
+	      return NULL_RTX;
+	    if (val == const1_rtx)
+	      return CONST1_RTX (mode);
+
+	    units = GET_MODE_NUNITS (mode);
+	    v = rtvec_alloc (units);
+	    for (i = 0; i < units; i++)
+	      RTVEC_ELT (v, i) = val;
+	    return gen_rtx_raw_CONST_VECTOR (mode, v);
+	  }
+#else
+	  return NULL_RTX;
 #endif
+	}
 
       return tem;
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 52522b8278c..5fc35b8cc98 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2004-10-09  Stuart Hastings  <stuart@apple.com>
+	    Roger Sayle  <roger@eyesopen.com>
+
+	PR rtl-optimization/17853
+	* gcc.dg/i386-mmx-5.c: New testcase.
+
 2004-10-09  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	* g++.dg/opt/pr17902.C: Fix typo in dg-do.
diff --git a/gcc/testsuite/gcc.dg/i386-mmx-5.c b/gcc/testsuite/gcc.dg/i386-mmx-5.c
new file mode 100644
index 00000000000..6021825a47d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/i386-mmx-5.c
@@ -0,0 +1,18 @@
+/* PR rtl-optimization/17853 */
+/* Contributed by Stuart Hastings <stuart@apple.com> */
+/* { dg-do compile { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-O2 -mmmx" } */
+#include <mmintrin.h>
+#include <stdlib.h>
+
+__m64 global_mask;
+
+int main()
+{
+    __m64 zero = _mm_setzero_si64();
+    __m64 mask = _mm_cmpeq_pi8( zero, zero );
+    mask = _mm_unpacklo_pi8( mask, zero );
+    global_mask = mask;
+    return 0;
+}
+