Hi,
This patch ports the logic from s390's TARGET_FLT_EVAL_METHOD to the new
target hook TARGET_C_EXCESS_PRECISION.
Patch tested by building an s390-none-linux toolchain and running
s390.exp (without the ability to execute) with no regressions, and manually
inspecting the output assembly code when compiling
testsuite/gcc.target/i386/excess-precision* to show no difference in
code-generation.
OK?
Thanks,
James
---
gcc/
2016-09-30 James Greenhalgh <james.greenha...@arm.com>
* config/s390/s390.c (s390_excess_precision): New.
(TARGET_C_EXCESS_PRECISION): Define.
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 3bdb648..b704d46 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -15106,6 +15106,34 @@ s390_invalid_binary_op (int op ATTRIBUTE_UNUSED, const_tree type1, const_tree ty
return NULL;
}
+/* Implement TARGET_EXCESS_PRECISION.
+
+ This is used by float.h to define the float_t and double_t data
+ types. For historical reasons both are double on s390 what cannot
+ be changed anymore. */
+
+static enum flt_eval_method
+s390_excess_precision (enum excess_precision_type type)
+{
+ switch (type)
+ {
+ case EXCESS_PRECISION_TYPE_FAST:
+ /* The fastest type to promote to will always be the native type,
+ whether that occurs with implicit excess precision or
+ otherwise. */
+ return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT;
+ case EXCESS_PRECISION_TYPE_STANDARD:
+ case EXCESS_PRECISION_TYPE_IMPLICIT:
+ /* Otherwise, the excess precision we want when we are
+ in a standards compliant mode, and the implicit precision we
+ provide can be identical. */
+ return FLT_EVAL_METHOD_PROMOTE_TO_DOUBLE;
+ default:
+ gcc_unreachable ();
+ }
+ return FLT_EVAL_METHOD_UNPREDICTABLE;
+}
+
/* Initialize GCC target structure. */
#undef TARGET_ASM_ALIGNED_HI_OP
@@ -15161,6 +15189,9 @@ s390_invalid_binary_op (int op ATTRIBUTE_UNUSED, const_tree type1, const_tree ty
#undef TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK hook_bool_const_tree_hwi_hwi_const_tree_true
+#undef TARGET_C_EXCESS_PRECISION
+#define TARGET_C_EXCESS_PRECISION s390_excess_precision
+
#undef TARGET_SCHED_ADJUST_PRIORITY
#define TARGET_SCHED_ADJUST_PRIORITY s390_adjust_priority
#undef TARGET_SCHED_ISSUE_RATE
