[PATCH][ARM] Enable code hoisting with -Os (PR80155)

[Wilco Dijkstra]

While code hoisting generally improves codesize, it can affect performance
negatively.  Benchmarking shows it doesn't help SPEC and negatively affects
embedded benchmarks, so only enable code hoisting with -Os on Arm.

Bootstrap OK, OK for commit?

ChangeLog:
2019-09-11  Wilco Dijkstra  <wdijk...@arm.com>


        PR tree-optimization/80155
        * common/config/arm/arm-common.c (arm_option_optimization_table):
        Enable -fcode-hoisting with -Os.

--
diff --git a/gcc/common/config/arm/arm-common.c 
b/gcc/common/config/arm/arm-common.c
index 
41a920f6dc96833e778faa8dbcc19beac483734c..b0d5fb300bf01acc1fb6f4631635f8a1bfe6441c
 100644
--- a/gcc/common/config/arm/arm-common.c
+++ b/gcc/common/config/arm/arm-common.c
@@ -39,6 +39,8 @@ static const struct default_options 
arm_option_optimization_table[] =
     /* Enable section anchors by default at -O1 or higher.  */
     { OPT_LEVELS_1_PLUS, OPT_fsection_anchors, NULL, 1 },
     { OPT_LEVELS_1_PLUS, OPT_fsched_pressure, NULL, 1 },
+    /* Enable code hoisting only with -Os.  */
+    { OPT_LEVELS_SIZE, OPT_fcode_hoisting, NULL, 1 },
     { OPT_LEVELS_NONE, 0, NULL, 0 }
   };