[PATCH] Move NOP stripping in SCEV analysis

[PATCH] Move NOP stripping in SCEV analysis

[Richard Biener]

The following moves a pair of STRIP_USELESS_TYPE_CONVERSIONS to
where it belongs and adds a comment on why we handle GENERIC
there at all.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	* tree-scalar-evolution.cc (follow_ssa_edge_expr): Move
	STRIP_USELESS_TYPE_CONVERSIONS to where it matters.
---
 gcc/tree-scalar-evolution.cc | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index 9f30f78cb5d..8b927094324 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -1214,6 +1214,8 @@ tail_recurse:
     {
       code = TREE_CODE (expr);
       type = TREE_TYPE (expr);
+      /* Via follow_ssa_edge_inner_loop_phi we arrive here with the
+	 GENERIC scalar evolution of the inner loop.  */
       switch (code)
 	{
 	CASE_CONVERT:
@@ -1224,6 +1226,8 @@ tail_recurse:
 	case MINUS_EXPR:
 	  rhs0 = TREE_OPERAND (expr, 0);
 	  rhs1 = TREE_OPERAND (expr, 1);
+	  STRIP_USELESS_TYPE_CONVERSION (rhs0);
+	  STRIP_USELESS_TYPE_CONVERSION (rhs1);
 	  break;
 	default:
 	  rhs0 = expr;
@@ -1260,8 +1264,6 @@ tail_recurse:
     case PLUS_EXPR:
     case MINUS_EXPR:
       /* This case is under the form "rhs0 +- rhs1".  */
-      STRIP_USELESS_TYPE_CONVERSION (rhs0);
-      STRIP_USELESS_TYPE_CONVERSION (rhs1);
       if (TREE_CODE (rhs0) == SSA_NAME
 	  && (TREE_CODE (rhs1) != SSA_NAME || code == MINUS_EXPR))
 	{
-- 
2.35.3