[rs6000] Use VIEW_CONVERT_EXPR to reinterpret vectors (PR 92515)

The new tree-cfg.c checking in r278245 tripped on folds of
ALTIVEC_BUILTIN_VPERM_*, which were using gimple_convert
rather than VIEW_CONVERT_EXPR to reinterpret the contents
of a vector as a different type.

2019-11-15  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR target/92515
	* config/rs6000/rs6000-call.c (rs6000_gimple_fold_builtin): Use
	VIEW_CONVERT_EXPR to reinterpret vectors as different types.

From-SVN: r278292

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d44f5a3..c2d3355 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-11-15  Richard Sandiford  <richard.sandiford@arm.com>
+
+       PR target/92515
+       * config/rs6000/rs6000-call.c (rs6000_gimple_fold_builtin): Use
+       VIEW_CONVERT_EXPR to reinterpret vectors as different types.
+
 2019-11-15  Kwok Cheung Yeung  <kcy@codesourcery.com>
 
        * config/gcn/gcn.c (gcn_regno_reg_class): Return VCC_CONDITIONAL_REG

diff --git a/gcc/config/rs6000/rs6000-call.c b/gcc/config/rs6000/rs6000-call.c
index 00ba745..85ff852 100644 (file)
--- a/gcc/config/rs6000/rs6000-call.c
+++ b/gcc/config/rs6000/rs6000-call.c
@@ -6173,13 +6173,16 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator *gsi)
        // convert arg0 and arg1 to match the type of the permute
        // for the VEC_PERM_EXPR operation.
        tree permute_type = (TREE_TYPE (permute));
-       tree arg0_ptype = gimple_convert (&stmts, loc, permute_type, arg0);
-       tree arg1_ptype = gimple_convert (&stmts, loc, permute_type, arg1);
+       tree arg0_ptype = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR,
+                                       permute_type, arg0);
+       tree arg1_ptype = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR,
+                                       permute_type, arg1);
        tree lhs_ptype = gimple_build (&stmts, loc, VEC_PERM_EXPR,
                                      permute_type, arg0_ptype, arg1_ptype,
                                      permute);
        // Convert the result back to the desired lhs type upon completion.
-       tree temp = gimple_convert (&stmts, loc, TREE_TYPE (lhs), lhs_ptype);
+       tree temp = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR,
+                                 TREE_TYPE (lhs), lhs_ptype);
        gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
        g = gimple_build_assign (lhs, temp);
        gimple_set_location (g, loc);