The heuristic introduced for PR71016 prevents recognizing a max / min
combo like it is used for
saturation when followed by a conversion.
The attached patch refines the heuristic to allow this case. Regression
tested on x86_64-pc-linux-gnu .
Index: tree-ssa-phiopt.c
===================================================================
--- tree-ssa-phiopt.c (revision 272846)
+++ tree-ssa-phiopt.c (working copy)
@@ -504,7 +504,18 @@ factor_out_conditional_conversion (edge
gsi = gsi_for_stmt (arg0_def_stmt);
gsi_prev_nondebug (&gsi);
if (!gsi_end_p (gsi))
- return NULL;
+ {
+ gimple *assign = gsi_stmt (gsi);
+ if (gimple_code (assign) != GIMPLE_ASSIGN)
+ return NULL;
+ tree lhs = gimple_assign_lhs (assign);
+ enum tree_code ass_code = gimple_assign_rhs_code (assign);
+ if (ass_code != MAX_EXPR && ass_code != MIN_EXPR)
+ return NULL;
+ gsi_prev_nondebug (&gsi);
+ if (!gsi_end_p (gsi))
+ return NULL;
+ }
gsi = gsi_for_stmt (arg0_def_stmt);
gsi_next_nondebug (&gsi);
if (!gsi_end_p (gsi))
Index: testsuite/gcc.dg/tree-ssa/pr66726-4.c
===================================================================
--- testsuite/gcc.dg/tree-ssa/pr66726-4.c (nonexistent)
+++ testsuite/gcc.dg/tree-ssa/pr66726-4.c (working copy)
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-phiopt1-details" } */
+
+#define SAT(x) (x < 0 ? 0 : (x > 255 ? 255 : x))
+
+void
+foo (unsigned char *p, int i)
+{
+ *p = SAT (i);
+}
+
+/* { dg-final { scan-tree-dump-times "COND_EXPR .*and PHI .*converted to
straightline code" 1 "phiopt1" } } */
