Re: [PATCH] openmp-simd-clone: Match shift type

[Andrew Stubbs]

On 29/07/2022 16:59, Jakub Jelinek wrote:
Doing the fold_convert seems to be a wasted effort to me.
Can't this be done conditional on whether some change is needed at all
and just using gimple_build_assign with NOP_EXPR, so something like:

I'm just not familiar enough with this stuff to run fold_convert in my 
head with confidence.

          tree shift_cvt_conv = shift_cnt;
          if (!useless_type_conversion_p (TREE_TYPE (mask),
                                          TREE_TYPE (shift_cnt)))
            {
              shift_cnt_conv = make_ssa_name (TREE_TYPE (mask));
              g = gimple_build_assign (shift_cnt_conv, NOP_EXPR, shift_cnt);
              gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
            }


Your version gives the same output mine does, at least on amdgcn anyway.

Am I OK to commit this version?

Andrew
openmp-simd-clone: Match shift types

Ensure that both parameters to vector shifts use the same mode.  This is most
important for amdgcn where the masks are DImode.

gcc/ChangeLog:

        * omp-simd-clone.cc (simd_clone_adjust): Convert shift_cnt to match
        the mask type.

Co-authored-by: Jakub Jelinek  <ja...@redhat.com>

diff --git a/gcc/omp-simd-clone.cc b/gcc/omp-simd-clone.cc
index 32649bc3f9a..58bd68b129b 100644
--- a/gcc/omp-simd-clone.cc
+++ b/gcc/omp-simd-clone.cc
@@ -1305,8 +1305,16 @@ simd_clone_adjust (struct cgraph_node *node)
                                       build_int_cst (TREE_TYPE (iter1), c));
              gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
            }
+         tree shift_cnt_conv = shift_cnt;
+         if (!useless_type_conversion_p (TREE_TYPE (mask),
+                                         TREE_TYPE (shift_cnt)))
+           {
+             shift_cnt_conv = make_ssa_name (TREE_TYPE (mask));
+             g = gimple_build_assign (shift_cnt_conv, NOP_EXPR, shift_cnt);
+             gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
+           }
          g = gimple_build_assign (make_ssa_name (TREE_TYPE (mask)),
-                                  RSHIFT_EXPR, mask, shift_cnt);
+                                  RSHIFT_EXPR, mask, shift_cnt_conv);
          gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
          mask = gimple_assign_lhs (g);
          g = gimple_build_assign (make_ssa_name (TREE_TYPE (mask)),