Hi Matt,
On 9/24/19 5:04 AM, Matt Turner wrote:
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=armv8-a
is treated as
$ gcc -march=armv8-a -march=native
Prune joined switches with Negative and RejectNegative to allow
-march=armv8-a to override previous -march=native on command-line.
This is the same fix as was applied for i386 in SVN revision 269164
but for
aarch64 and arm.
The fix is ok for arm and LGTM for aarch64 FWIW.
How has this been tested?
However...
gcc/
PR driver/69471
* config/aarch64/aarch64.opt (march=): Add Negative(march=).
(mtune=): Add Negative(mtune=).
* config/arm/arm.opt: Likewise.
---
gcc/config/aarch64/aarch64.opt | 5 +++--
gcc/config/arm/arm.opt | 4 ++--
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.opt
b/gcc/config/aarch64/aarch64.opt
index 865b6a6d8ca..908dca23b3c 100644
--- a/gcc/config/aarch64/aarch64.opt
+++ b/gcc/config/aarch64/aarch64.opt
@@ -119,7 +119,8 @@ EnumValue
Enum(aarch64_tls_size) String(48) Value(48)
march=
-Target RejectNegative ToLower Joined Var(aarch64_arch_string)
+Target RejectNegative Negative(march=) ToLower Joined
Var(aarch64_arch_string)
+
Use features of architecture ARCH.
mcpu=
... Looks like we'll need something similar for -mcpu. On arm and
aarch64 the -mcpu is the most commonly used option and that can also
take a "native" value that would suffer from the same issue I presume.
Thanks,
Kyrill
@@ -127,7 +128,7 @@ Target RejectNegative ToLower Joined
Var(aarch64_cpu_string)
Use features of and optimize for CPU.
mtune=
-Target RejectNegative ToLower Joined Var(aarch64_tune_string)
+Target RejectNegative Negative(mtune=) ToLower Joined
Var(aarch64_tune_string)
Optimize for CPU.
mabi=
diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index 452f0cf6d67..e3ead5c95d1 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -82,7 +82,7 @@ mapcs-stack-check
Target Report Mask(APCS_STACK) Undocumented
march=
-Target RejectNegative ToLower Joined Var(arm_arch_string)
+Target RejectNegative Negative(march=) ToLower Joined
Var(arm_arch_string)
Specify the name of the target architecture.
; Other arm_arch values are loaded from arm-tables.opt
@@ -232,7 +232,7 @@ Target Report Mask(TPCS_LEAF_FRAME)
Thumb: Generate (leaf) stack frames even if not needed.
mtune=
-Target RejectNegative ToLower Joined Var(arm_tune_string)
+Target RejectNegative Negative(mtune=) ToLower Joined
Var(arm_tune_string)
Tune code for the given processor.
mprint-tune-info
--
2.21.0
