slp: Split out patterns away from using SLP_ONLY into their own flag

Previously the SLP pattern matcher was using STMT_VINFO_SLP_VECT_ONLY as a way
to dissolve the SLP only patterns during SLP cancellation.  However it seems
like the semantics for STMT_VINFO_SLP_VECT_ONLY are slightly different than what
I expected.

Namely that the non-SLP path can still use a statement marked
STMT_VINFO_SLP_VECT_ONLY.  One such example is masked loads which are used both
in the SLP and non-SLP path.

To fix this I now introduce a new flag STMT_VINFO_SLP_VECT_ONLY_PATTERN which is
used only by the pattern matcher.

gcc/ChangeLog:

	PR tree-optimization/98928
	* tree-vect-loop.c (vect_analyze_loop_2): Change
	STMT_VINFO_SLP_VECT_ONLY to STMT_VINFO_SLP_VECT_ONLY_PATTERN.
	* tree-vect-slp-patterns.c (complex_pattern::build): Likewise.
	* tree-vectorizer.h (STMT_VINFO_SLP_VECT_ONLY_PATTERN): New.
	(class _stmt_vec_info): Add slp_vect_pattern_only_p.

gcc/testsuite/ChangeLog:

	PR tree-optimization/98928
	* gcc.target/i386/pr98928.c: New test.

4 files changed, 66 insertions, 2 deletions

diff --git a/gcc/testsuite/gcc.target/i386/pr98928.c b/gcc/testsuite/gcc.target/i386/pr98928.c
new file mode 100644
index 00000000000..9503b579a88
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr98928.c
@@ -0,0 +1,59 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-Ofast -march=skylake-avx512 -fwhole-program -w" } */
+
+typedef float MagickRealType;
+typedef short Quantum;
+float InterpolateMagickPixelPacket_alpha[1];
+int InterpolateMagickPixelPacket_i;
+
+void InterpolateMagickPixelPacket();
+
+void main() { InterpolateMagickPixelPacket(); }
+
+typedef struct {
+  MagickRealType red, green, blue, opacity, index;
+} MagickPixelPacket;
+typedef struct {
+  Quantum blue, green, red, opacity;
+} PixelPacket;
+struct _Image {
+  int colorspace;
+  int matte;
+} GetMagickPixelPacket(MagickPixelPacket *pixel) {
+  pixel->red = pixel->green = pixel->blue = 0.0;
+}
+int AlphaBlendMagickPixelPacket(struct _Image *image, PixelPacket *color,
+                            Quantum *indexes, MagickPixelPacket *pixel,
+                            MagickRealType *alpha) {
+  if (image->matte) {
+    *alpha = pixel->red = pixel->green = pixel->blue = pixel->opacity =
+        color->opacity;
+    pixel->index = 0.0;
+    if (image->colorspace)
+      pixel->index = *indexes;
+    return 0;
+  }
+  *alpha = 1.0 / 0.2;
+  pixel->red = *alpha * color->red;
+  pixel->green = *alpha * color->green;
+  pixel->blue = *alpha * color->blue;
+  pixel->opacity = pixel->index = 0.0;
+  if (image->colorspace && indexes)
+    pixel->index = *indexes;
+}
+MagickPixelPacket InterpolateMagickPixelPacket_pixels[1];
+PixelPacket InterpolateMagickPixelPacket_p;
+
+void
+InterpolateMagickPixelPacket(struct _Image *image) {
+  Quantum *indexes;
+  for (; InterpolateMagickPixelPacket_i; InterpolateMagickPixelPacket_i++) {
+    GetMagickPixelPacket(InterpolateMagickPixelPacket_pixels +
+                         InterpolateMagickPixelPacket_i);
+    AlphaBlendMagickPixelPacket(
+        image, &InterpolateMagickPixelPacket_p + InterpolateMagickPixelPacket_i,
+        indexes + InterpolateMagickPixelPacket_i,
+        InterpolateMagickPixelPacket_pixels + InterpolateMagickPixelPacket_i,
+        InterpolateMagickPixelPacket_alpha + InterpolateMagickPixelPacket_i);
+  }
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index acfd1952e3b..200ed27b32e 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -2700,7 +2700,7 @@ again:
 	    {
 	      stmt_vec_info pattern_stmt_info
 		= STMT_VINFO_RELATED_STMT (stmt_info);
-	      if (STMT_VINFO_SLP_VECT_ONLY (pattern_stmt_info))
+	      if (STMT_VINFO_SLP_VECT_ONLY_PATTERN (pattern_stmt_info))
 		STMT_VINFO_IN_PATTERN_P (stmt_info) = false;
 
 	      gimple *pattern_def_seq = STMT_VINFO_PATTERN_DEF_SEQ (stmt_info);
diff --git a/gcc/tree-vect-slp-patterns.c b/gcc/tree-vect-slp-patterns.c
index d25560fab97..f0817da9f62 100644
--- a/gcc/tree-vect-slp-patterns.c
+++ b/gcc/tree-vect-slp-patterns.c
@@ -599,7 +599,7 @@ complex_pattern::build (vec_info *vinfo)
 	 the call there.  */
       vect_mark_pattern_stmts (vinfo, stmt_info, call_stmt,
 			       SLP_TREE_VECTYPE (node));
-      STMT_VINFO_SLP_VECT_ONLY (call_stmt_info) = true;
+      STMT_VINFO_SLP_VECT_ONLY_PATTERN (call_stmt_info) = true;
 
       /* Since we are replacing all the statements in the group with the same
 	 thing it doesn't really matter.  So just set it every time a new stmt
diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h
index f8bf4488d0e..e564fcf835a 100644
--- a/gcc/tree-vectorizer.h
+++ b/gcc/tree-vectorizer.h
@@ -1215,6 +1215,10 @@ public:
 
   /* True if this is only suitable for SLP vectorization.  */
   bool slp_vect_only_p;
+
+  /* True if this is a pattern that can only be handled by SLP
+     vectorization.  */
+  bool slp_vect_pattern_only_p;
 };
 
 /* Information about a gather/scatter call.  */
@@ -1301,6 +1305,7 @@ struct gather_scatter_info {
 #define STMT_VINFO_REDUC_VECTYPE(S)     (S)->reduc_vectype
 #define STMT_VINFO_REDUC_VECTYPE_IN(S)  (S)->reduc_vectype_in
 #define STMT_VINFO_SLP_VECT_ONLY(S)     (S)->slp_vect_only_p
+#define STMT_VINFO_SLP_VECT_ONLY_PATTERN(S) (S)->slp_vect_pattern_only_p
 
 #define DR_GROUP_FIRST_ELEMENT(S) \
   (gcc_checking_assert ((S)->dr_aux.dr), (S)->first_element)