From: Richard Biener <rguenther@suse.de>
Date: Wed, 14 May 2025 14:45:08 +0000 (+0200)
Subject: Enhance -fopt-info-vec vectorized loop diagnostic
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=af7b84d0d02ffa23e4843e9555a888c9e80bd9b5;p=thirdparty%2Fgcc.git

Enhance -fopt-info-vec vectorized loop diagnostic

The following includes whether we vectorize an epilogue, whether
we use loop masking and what vectorization factor (unroll factor)
we use.  So it's now

t.c:4:21: optimized: loop vectorized using 64 byte vectors and unroll factor 32
t.c:4:21: optimized: epilogue loop vectorized using masked 64 byte vectors and unroll factor 32

for a masked epilogue with AVX512 and HImode data for example.  Rather
than

t.c:4:21: optimized: loop vectorized using 64 byte vectors
t.c:4:21: optimized: loop vectorized using 64 byte vectors

I verified we don't translate opt-info messages and thus excessive
use of %s to compose the strings should be OK.

	* tree-vectorizer.cc (vect_transform_loops): When diagnosing
	a vectorized loop indicate whether we vectorized an epilogue,
	whether we used masked vectors and what unroll factor was
	used.

	* gcc.target/i386/pr110310.c: Adjust.
---

diff --git a/gcc/testsuite/gcc.target/i386/pr110310.c b/gcc/testsuite/gcc.target/i386/pr110310.c
index dce388aeb20..60564393a2c 100644
--- a/gcc/testsuite/gcc.target/i386/pr110310.c
+++ b/gcc/testsuite/gcc.target/i386/pr110310.c
@@ -9,5 +9,5 @@ void foo (int * __restrict a, int *b)
 
 /* We should vectorize the main loop with AVX512 and the epilog with SSE.  */
 
-/* { dg-final { scan-tree-dump "optimized: loop vectorized using 64 byte vectors" "vect" } } */
-/* { dg-final { scan-tree-dump "optimized: loop vectorized using 16 byte vectors" "vect" } } */
+/* { dg-final { scan-tree-dump "loop vectorized using 64 byte vectors" "vect" } } */
+/* { dg-final { scan-tree-dump "loop vectorized using 16 byte vectors" "vect" } } */
diff --git a/gcc/tree-vectorizer.cc b/gcc/tree-vectorizer.cc
index 447f882c518..2f77e46ba99 100644
--- a/gcc/tree-vectorizer.cc
+++ b/gcc/tree-vectorizer.cc
@@ -1026,10 +1026,19 @@ vect_transform_loops (hash_table<simduid_to_vf> *&simduid_to_vf_htab,
     {
       if (GET_MODE_SIZE (loop_vinfo->vector_mode).is_constant (&bytes))
 	dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
-			 "loop vectorized using %wu byte vectors\n", bytes);
+			 "%sloop vectorized using %s%wu byte vectors and"
+			 " unroll factor %u\n",
+			 LOOP_VINFO_EPILOGUE_P (loop_vinfo)
+			 ? "epilogue " : "",
+			 LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo)
+			 ? "masked " : "", bytes,
+			 (unsigned int) LOOP_VINFO_VECT_FACTOR
+						 (loop_vinfo).to_constant ());
       else
 	dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location,
-			 "loop vectorized using variable length vectors\n");
+			 "%sloop vectorized using variable length vectors\n",
+			 LOOP_VINFO_EPILOGUE_P (loop_vinfo)
+			 ? "epilogue " : "");
     }
 
   loop_p new_loop = vect_transform_loop (loop_vinfo,