From: Luis Silva <[email protected]>
For ARC EM CPUs that enable code density by default, the driver adds
-mcode-density to the assembler command line. When the user passes
-mno-code-density, the compiler disables the extension, but the driver
still passes -mcode-density to the assembler for those CPUs.
For example, with -mcpu=em4_dmips the driver invokes the assembler as:
gcc ... -mcpu=em4_dmips -c test.c
-> as ... -mcpu=arcem -mcode-density ...
With -mno-code-density, it used to make no difference:
gcc ... -mcpu=em4_dmips -mno-code-density -c test.c
-> as ... -mcpu=arcem -mcode-density ...
and now correctly omits -mcode-density:
gcc ... -mcpu=em4_dmips -mno-code-density -c test.c
-> as ... -mcpu=arcem ...
Assembling the same test program shows different instruction encodings
in the object file, for example:
$ gcc -c test.c -mcpu=em4_dmips
$ objdump -d test.o
4: 4104 ld_s r1,[r0,0]
10: 4004 ld_s r0,[r0,0]
versus:
$ gcc -c test.c -mcpu=em4_dmips -mno-code-density
$ objdump -d test.o
4: 8020 ld_s r1,[r0,0]
10: 8000 ld_s r0,[r0,0]
gcc/ChangeLog:
* config/arc/arc.h (arc_cd_to_as): Declare.
(EXTRA_SPEC_FUNCTIONS): Register cd_to_as.
(ASM_SPEC): Call cd_to_as with the CPU name and code-density
markers from -mcode-density/-mno-code-density.
* config/arc/driver-arc.cc (arc_lookup_cpu): New helper.
(arc_cpu_to_as): Drop code-density handling.
(arc_cd_to_as): New spec function; add -mcode-density only when
appropriate, and omit it for -mno-code-density.
Signed-off-by: Luis Silva <[email protected]>
---
gcc/config/arc/arc.h | 9 +++--
gcc/config/arc/driver-arc.cc | 66 +++++++++++++++++++++++++-----------
2 files changed, 53 insertions(+), 22 deletions(-)
diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
index f2a4f0de701..934ac6f89f4 100644
--- a/gcc/config/arc/arc.h
+++ b/gcc/config/arc/arc.h
@@ -70,9 +70,11 @@ along with GCC; see the file COPYING3. If not see
%{G*} \
"
extern const char *arc_cpu_to_as (int argc, const char **argv);
+extern const char *arc_cd_to_as (int argc, const char **argv);
#define EXTRA_SPEC_FUNCTIONS \
- { "cpu_to_as", arc_cpu_to_as },
+ { "cpu_to_as", arc_cpu_to_as }, \
+ { "cd_to_as", arc_cd_to_as },
/* This macro defines names of additional specifications to put in the specs
that can be used in various specifications like CC1_SPEC. Its definition
@@ -97,8 +99,9 @@ extern const char *arc_cpu_to_as (int argc, const char
**argv);
#undef ASM_SPEC
#define ASM_SPEC "%{mbig-endian|EB:-EB} %{EL} " \
- "%:cpu_to_as(%{mcpu=*:%*}) %{mspfp*} %{mdpfp*} " \
- "%{mfpu=fpuda*:-mfpuda} %{mcode-density}"
+ "%:cpu_to_as(%{mcpu=*:%*}) " \
+ "%:cd_to_as(%{mcpu=*:%*} %{mno-code-density:no-cd;mcode-density:cd}) " \
+ "%{mspfp*} %{mdpfp*} %{mfpu=fpuda*:-mfpuda}"
/* Support for a compile-time default CPU and FPU. The rules are:
--with-cpu is ignored if -mcpu, mARC*, marc*, mA7, mA6 are specified.
diff --git a/gcc/config/arc/driver-arc.cc b/gcc/config/arc/driver-arc.cc
index b70b21cf231..b3efe87c67e 100644
--- a/gcc/config/arc/driver-arc.cc
+++ b/gcc/config/arc/driver-arc.cc
@@ -25,6 +25,25 @@
#include "coretypes.h"
#include "tm.h"
+/* Look up the CPU given by NAME, or the default CPU if NAME is NULL. */
+
+static const arc_cpu_t *
+arc_lookup_cpu (const char *name)
+{
+ if (name == NULL)
+ return &arc_cpu_types[(int) TARGET_CPU_DEFAULT];
+
+ for (const arc_cpu_t *arc_selected_cpu = arc_cpu_types;
+ arc_selected_cpu->name;
+ arc_selected_cpu++)
+ {
+ if (strcmp (arc_selected_cpu->name, name) == 0)
+ return arc_selected_cpu;
+ }
+
+ gcc_unreachable ();
+}
+
/* Returns command line parameters to pass to as. */
const char*
@@ -33,29 +52,12 @@ arc_cpu_to_as (int argc, const char **argv)
const char *name = NULL;
const arc_cpu_t *arc_selected_cpu;
- /* No argument, check what is the default cpu. */
- if (argc == 0)
- {
- arc_selected_cpu = &arc_cpu_types[(int) TARGET_CPU_DEFAULT];
- }
- else
- {
- name = argv[0];
- for (arc_selected_cpu = arc_cpu_types; arc_selected_cpu->name;
- arc_selected_cpu++)
- {
- if (strcmp (arc_selected_cpu->name, name) == 0)
- break;
- }
- }
+ arc_selected_cpu = arc_lookup_cpu (argc == 0 ? NULL : argv[0]);
switch (arc_selected_cpu->arch_info->arch_id)
{
case BASE_ARCH_em:
- if (arc_selected_cpu->flags & FL_CD)
- name = "-mcode-density";
- else
- name = "";
+ name = "";
if (arc_selected_cpu->flags & FL_FPUDA)
name = concat ("-mfpuda ", name, NULL);
if (arc_selected_cpu->flags & FL_SPFP)
@@ -81,3 +83,29 @@ arc_cpu_to_as (int argc, const char **argv)
}
return NULL;
}
+
+/* Returns code density parameters to pass to as. */
+
+const char *
+arc_cd_to_as (int argc, const char **argv)
+{
+ const char *name = NULL;
+ const arc_cpu_t *arc_selected_cpu;
+
+ for (int i = 0; i < argc; i++)
+ {
+ if (strcmp (argv[i], "no-cd") == 0)
+ return "";
+ else if (strcmp (argv[i], "cd") == 0)
+ return "-mcode-density";
+ else
+ name = argv[i];
+ }
+
+ arc_selected_cpu = arc_lookup_cpu (name);
+ if (arc_selected_cpu->arch_info->arch_id == BASE_ARCH_em
+ && (arc_selected_cpu->flags & FL_CD))
+ return "-mcode-density";
+
+ return "";
+}
--
2.47.3
