Most any compilation on ARM/AArch64 was warning because the default L1 cache
line size of 32B was smaller than the default
std::hardware_constructive_interference_size of 64B. This is mostly due to
inaccurate --param l1-cache-line-size, but it's not helpful to complain to a
user that didn't set the values.
gcc/cp/ChangeLog:
* decl.c (cxx_init_decl_processing): Only warn about odd
interference sizes if they were specified with --param.
---
gcc/cp/decl.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1a2925b4108..9ad9446e262 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4756,7 +4756,7 @@ cxx_init_decl_processing (void)
/* Check that the hardware interference sizes are at least
alignof(max_align_t), as required by the standard. */
const int max_align = max_align_t_align () / BITS_PER_UNIT;
- if (param_destruct_interfere_size)
+ if (global_options_set.x_param_destruct_interfere_size)
{
if (param_destruct_interfere_size < max_align)
error ("%<--param destructive-interference-size=%d%> is less than "
@@ -4767,11 +4767,13 @@ cxx_init_decl_processing (void)
"is less than %<--param l1-cache-line-size=%d%>",
param_destruct_interfere_size, param_l1_cache_line_size);
}
+ else if (param_destruct_interfere_size)
+ /* Assume the internal value is OK. */;
else if (param_l1_cache_line_size >= max_align)
param_destruct_interfere_size = param_l1_cache_line_size;
/* else leave it unset. */
- if (param_construct_interfere_size)
+ if (global_options_set.x_param_construct_interfere_size)
{
if (param_construct_interfere_size < max_align)
error ("%<--param constructive-interference-size=%d%> is less than "
@@ -4783,6 +4785,8 @@ cxx_init_decl_processing (void)
"is greater than %<--param l1-cache-line-size=%d%>",
param_construct_interfere_size, param_l1_cache_line_size);
}
+ else if (param_construct_interfere_size)
+ /* Assume the internal value is OK. */;
else if (param_l1_cache_line_size >= max_align)
param_construct_interfere_size = param_l1_cache_line_size;
}
base-commit: adddfc85c07143f7c8097a90a83bfb15b8bd52e8
--
2.27.0
