When -march=native is passed to host_detect_local_cpu to the backend,
it overrides all command lines after it. That means
$ gcc -march=native -march=skylake-avx512
is the treated as
$ gcc -march=skylake-avx512 -march=native
Prune joined switches with negation to allow -march=skylake-avx512 to
override previous -march=native on command-line.
PR driver/69471
* opts-common.c (prune_options): Also prune joined switches
with negation.
* config/i386/i386.opt (march=): Add Negative(march=).
(mtune=): Add Negative(mtune=).
---
gcc/config/i386/i386.opt | 4 ++--
gcc/opts-common.c | 7 ++++---
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 9b93241f790..b7998ee7363 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -253,7 +253,7 @@ EnumValue
Enum(ix86_align_data) String(cacheline) Value(ix86_align_data_type_cacheline)
march=
-Target RejectNegative Joined Var(ix86_arch_string)
+Target RejectNegative Negative(march=) Joined Var(ix86_arch_string)
Generate code for given CPU.
masm=
@@ -510,7 +510,7 @@ Target Report Mask(TLS_DIRECT_SEG_REFS)
Use direct references against %gs when accessing tls data.
mtune=
-Target RejectNegative Joined Var(ix86_tune_string)
+Target RejectNegative Negative(mtune=) Joined Var(ix86_tune_string)
Schedule code for given CPU.
mtune-ctrl=
diff --git a/gcc/opts-common.c b/gcc/opts-common.c
index ee8898b22ec..ba9eb144078 100644
--- a/gcc/opts-common.c
+++ b/gcc/opts-common.c
@@ -1014,8 +1014,8 @@ prune_options (struct cl_decoded_option **decoded_options,
if (option->neg_index < 0)
goto keep;
- /* Skip joined switches. */
- if ((option->flags & CL_JOINED))
+ /* Skip joined switches if there is no negation. */
+ if ((option->flags & CL_JOINED) && option->neg_index < 0)
goto keep;
for (j = i + 1; j < old_decoded_options_count; j++)
@@ -1027,7 +1027,8 @@ prune_options (struct cl_decoded_option **decoded_options,
continue;
if (cl_options[next_opt_idx].neg_index < 0)
continue;
- if ((cl_options[next_opt_idx].flags & CL_JOINED))
+ if ((cl_options[next_opt_idx].flags & CL_JOINED)
+ && cl_options[next_opt_idx].neg_index < 0)
continue;
if (cancel_option (opt_idx, next_opt_idx, next_opt_idx))
break;
--
2.20.1
