| Message ID | 560D2E79.90700@arm.com |
|---|---|
| State | New |
| Headers | show |
Ping. This almost fell through the cracks. https://gcc.gnu.org/ml/gcc-patches/2015-10/msg00055.html Thanks, Kyrill On 01/10/15 14:00, Kyrill Tkachov wrote: > Hi all, > > As part of the SWITCHABLE_TARGET work I inadvertently changed the behaviour of -mgeneral-regs-only with respect to the .arch directives that we emit. > The behaviour of -mgeneral-regs-only in GCC 5 and earlier is such that it disallows the usage of FP/SIMD registers but does *not* stop the compiler from > emitting the +fp,+simd etc extensions in the .arch directive of the generated assembly. This is to accommodate users who may want to write inline assembly > in a file compiled with -mgeneral-regs-only. > > This patch restores the trunk behaviour in that respect to that of GCC 5 and the documentation for the option is tweaked a bit to reflect that. > Bootstrapped and tested on aarch64. > > Ok for trunk? > > Thanks, > Kyrill > > 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> > > * config/aarch64/aarch64.c (aarch64_override_options_internal): > Do not alter target_flags due to TARGET_GENERAL_REGS_ONLY_P. > * doc/invoke.texi (AArch64 options): Mention that -mgeneral-regs-only > does not affect the assembler directives. > > 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> > > * gcc.target/aarch64/mgeneral-regs_4.c: New test.
On 04/12/15 14:40, Kyrill Tkachov wrote: > Ping. > This almost fell through the cracks. > https://gcc.gnu.org/ml/gcc-patches/2015-10/msg00055.html > > Thanks, > Kyrill > > On 01/10/15 14:00, Kyrill Tkachov wrote: >> Hi all, >> >> As part of the SWITCHABLE_TARGET work I inadvertently changed the >> behaviour of -mgeneral-regs-only with respect to the .arch directives >> that we emit. >> The behaviour of -mgeneral-regs-only in GCC 5 and earlier is such that >> it disallows the usage of FP/SIMD registers but does *not* stop the >> compiler from >> emitting the +fp,+simd etc extensions in the .arch directive of the >> generated assembly. This is to accommodate users who may want to write >> inline assembly >> in a file compiled with -mgeneral-regs-only. >> >> This patch restores the trunk behaviour in that respect to that of GCC >> 5 and the documentation for the option is tweaked a bit to reflect that. >> Bootstrapped and tested on aarch64. >> >> Ok for trunk? >> >> Thanks, >> Kyrill >> >> 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> >> >> * config/aarch64/aarch64.c (aarch64_override_options_internal): >> Do not alter target_flags due to TARGET_GENERAL_REGS_ONLY_P. >> * doc/invoke.texi (AArch64 options): Mention that >> -mgeneral-regs-only >> does not affect the assembler directives. >> >> 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> >> >> * gcc.target/aarch64/mgeneral-regs_4.c: New test. > OK /M
commit bd99347f0dad9346dc16ffc13cd423a4889ae339
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Fri Sep 11 09:40:44 2015 +0100
[AArch64] Don't allow -mgeneral-regs-only to change the .arch assembler directives
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 115c3a7..81e0eb0 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -7658,19 +7658,6 @@ aarch64_override_options_internal (struct gcc_options *opts)
if (opts->x_flag_strict_volatile_bitfields < 0 && abi_version_at_least (2))
opts->x_flag_strict_volatile_bitfields = 1;
- /* -mgeneral-regs-only sets a mask in target_flags, make sure that
- aarch64_isa_flags does not contain the FP/SIMD/Crypto feature flags
- in case some code tries reading aarch64_isa_flags directly to check if
- FP is available. Reuse the aarch64_parse_extension machinery since it
- knows how to disable any other flags that fp implies. */
- if (TARGET_GENERAL_REGS_ONLY_P (opts->x_target_flags))
- {
- /* aarch64_parse_extension takes char* rather than const char* because
- it is usually called from within other parsing functions. */
- char tmp_str[] = "+nofp";
- aarch64_parse_extension (tmp_str, &opts->x_aarch64_isa_flags);
- }
-
initialize_aarch64_code_model (opts);
initialize_aarch64_tls_size (opts);
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 547ee2d..e8067f2 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -12304,10 +12304,9 @@ Generate big-endian code. This is the default when GCC is configured for an
@item -mgeneral-regs-only
@opindex mgeneral-regs-only
-Generate code which uses only the general-purpose registers. This is equivalent
-to feature modifier @option{nofp} of @option{-march} or @option{-mcpu}, except
-that @option{-mgeneral-regs-only} takes precedence over any conflicting feature
-modifier regardless of sequence.
+Generate code which uses only the general-purpose registers. This will prevent
+the compiler from using floating-point and Advanced SIMD registers but will not
+impose any restrictions on the assembler.
@item -mlittle-endian
@opindex mlittle-endian
diff --git a/gcc/testsuite/gcc.target/aarch64/mgeneral-regs_4.c b/gcc/testsuite/gcc.target/aarch64/mgeneral-regs_4.c
new file mode 100644
index 0000000..8eb50aa
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/mgeneral-regs_4.c
@@ -0,0 +1,9 @@
+/* { dg-options "-mgeneral-regs-only -march=armv8-a+simd+fp -O2" } */
+
+int
+test (void)
+{
+ return 1;
+}
+
+/* { dg-final { scan-assembler "\.arch.*fp.*simd" } } */
Hi all, As part of the SWITCHABLE_TARGET work I inadvertently changed the behaviour of -mgeneral-regs-only with respect to the .arch directives that we emit. The behaviour of -mgeneral-regs-only in GCC 5 and earlier is such that it disallows the usage of FP/SIMD registers but does *not* stop the compiler from emitting the +fp,+simd etc extensions in the .arch directive of the generated assembly. This is to accommodate users who may want to write inline assembly in a file compiled with -mgeneral-regs-only. This patch restores the trunk behaviour in that respect to that of GCC 5 and the documentation for the option is tweaked a bit to reflect that. Bootstrapped and tested on aarch64. Ok for trunk? Thanks, Kyrill 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> * config/aarch64/aarch64.c (aarch64_override_options_internal): Do not alter target_flags due to TARGET_GENERAL_REGS_ONLY_P. * doc/invoke.texi (AArch64 options): Mention that -mgeneral-regs-only does not affect the assembler directives. 2015-10-01 Kyrylo Tkachov <kyrylo.tkachov@arm.com> * gcc.target/aarch64/mgeneral-regs_4.c: New test.