[PATCH] tree-optimization/121059 - record loop mask when required

[Richard Biener]

For loop masking we need to mask a mask AND operation with the loop
mask.  The following makes sure we have a corresponding mask
available.  There's no good way to distinguish loop masking from
len masking here, so assume we have recorded a mask for the operands
mask producers.

Bootstrap and regtest running on x86_64-unknown-linux-gnu.

        PR tree-optimization/121059
        * tree-vect-stmts.cc (vectorizable_operation): Record a
        loop mask for mask AND operations.

        * gcc.dg/vect/pr121059.c: New testcase.
---
 gcc/testsuite/gcc.dg/vect/pr121059.c | 24 ++++++++++++++++++++++++
 gcc/tree-vect-stmts.cc               | 10 ++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/vect/pr121059.c

diff --git a/gcc/testsuite/gcc.dg/vect/pr121059.c 
b/gcc/testsuite/gcc.dg/vect/pr121059.c
new file mode 100644
index 00000000000..d7f69b4f1f5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr121059.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O3 --param vect-partial-vector-usage=1" } */
+/* { dg-additional-options "-march=x86-64-v4" { target avx512f } } */
+
+typedef struct {
+  long left, right, top, bottom;
+} MngBox;
+typedef struct {
+  MngBox object_clip[6];
+  char exists[256], frozen[];
+} MngReadInfo;
+MngReadInfo mng_info;
+
+long ReadMNGImage_i;
+
+void ReadMNGImage(int ReadMNGImage_i)
+{
+  for (; ReadMNGImage_i < 256; ReadMNGImage_i++)
+    if (mng_info.exists[ReadMNGImage_i] && mng_info.frozen[ReadMNGImage_i])
+      mng_info.object_clip[ReadMNGImage_i].left =
+          mng_info.object_clip[ReadMNGImage_i].right =
+              mng_info.object_clip[ReadMNGImage_i].top =
+                  mng_info.object_clip[ReadMNGImage_i].bottom = 0;
+}
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 4aa69da2218..f0dc4843ca7 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -6978,6 +6978,16 @@ vectorizable_operation (vec_info *vinfo,
              LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo) = false;
            }
        }
+      else if (loop_vinfo
+              && LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo)
+              && code == BIT_AND_EXPR
+              && VECTOR_BOOLEAN_TYPE_P (vectype)
+              /* We cannot always record a mask since that will disable
+                 len-based partial vectors, but there should be already
+                 one mask producer stmt which should require loop
+                 masking.  */
+              && !masks->is_empty ())
+       vect_record_loop_mask (loop_vinfo, masks, vec_num, vectype, NULL);

       /* Put types on constant and invariant SLP children.  */
       if (!vect_maybe_update_slp_op_vectype (slp_op0, vectype)
--
2.43.0