From: Jan Beulich <jbeulich@suse.com>
To: Binutils <binutils@sourceware.org>
Subject: [PATCH 7/7] x86: introduce a state stack for .arch
Date: Thu, 30 Jun 2022 14:55:46 +0200 [thread overview]
Message-ID: <53e719d3-482e-e1bc-663c-367fe0de7277@suse.com> (raw)
In-Reply-To: <01f502ff-5b51-86d3-ed54-646df7d22037@suse.com>
When using just slightly non-trivial combinations of .arch, it can be
quite useful to be able to go back to prior state without needing to
re-invoke perhaps many earlier directives and without needing to invoke
perhaps many "negative" ones. Like some other architectures allow
saving (pushing) and restoring (popping) present/prior state.
For now require the same .code<N> to be in effect for ".arch pop" that
was in effect for the corresponding ".arch push".
Also change the global "no_cond_jump_promotion" to be bool, to match the
new struct field.
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -788,7 +788,7 @@ i386_cpu_flags cpu_arch_isa_flags;
/* If set, conditional jumps are not automatically promoted to handle
larger than a byte offset. */
-static unsigned int no_cond_jump_promotion = 0;
+static bool no_cond_jump_promotion = false;
/* Encode SSE instructions with VEX prefix. */
static unsigned int sse2avx;
@@ -2663,6 +2663,20 @@ extend_cpu_sub_arch_name (const char *na
static void
set_cpu_arch (int dummy ATTRIBUTE_UNUSED)
{
+ typedef struct arch_stack_entry
+ {
+ const struct arch_stack_entry *prev;
+ const char *name;
+ char *sub_name;
+ i386_cpu_flags flags;
+ i386_cpu_flags isa_flags;
+ enum processor_type isa;
+ enum flag_code flag_code;
+ char stackop_size;
+ bool no_cond_jump_promotion;
+ } arch_stack_entry;
+ static const arch_stack_entry *arch_stack_top;
+
SKIP_WHITESPACE ();
if (!is_end_of_line[(unsigned char) *input_line_pointer])
@@ -2706,6 +2720,67 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED
j = ARRAY_SIZE (cpu_arch) + 1;
}
}
+ else if (strcmp (string, "push") == 0)
+ {
+ arch_stack_entry *top = XNEW (arch_stack_entry);
+
+ top->name = cpu_arch_name;
+ if (cpu_sub_arch_name)
+ top->sub_name = xstrdup (cpu_sub_arch_name);
+ else
+ top->sub_name = NULL;
+ top->flags = cpu_arch_flags;
+ top->isa = cpu_arch_isa;
+ top->isa_flags = cpu_arch_isa_flags;
+ top->flag_code = flag_code;
+ top->stackop_size = stackop_size;
+ top->no_cond_jump_promotion = no_cond_jump_promotion;
+
+ top->prev = arch_stack_top;
+ arch_stack_top = top;
+
+ (void) restore_line_pointer (e);
+ demand_empty_rest_of_line ();
+ return;
+ }
+ else if (strcmp (string, "pop") == 0)
+ {
+ const arch_stack_entry *top = arch_stack_top;
+
+ if (!top)
+ as_bad (_(".arch stack is empty"));
+ else if (top->flag_code != flag_code
+ || top->stackop_size != stackop_size)
+ {
+ static const unsigned int bits[] = {
+ [CODE_16BIT] = 16,
+ [CODE_32BIT] = 32,
+ [CODE_64BIT] = 64,
+ };
+
+ as_bad (_("this `.arch pop' requires `.code%u%s' to be in effect"),
+ bits[top->flag_code],
+ top->stackop_size == LONG_MNEM_SUFFIX ? "gcc" : "");
+ }
+ else
+ {
+ arch_stack_top = top->prev;
+
+ cpu_arch_name = top->name;
+ xfree (cpu_sub_arch_name);
+ cpu_sub_arch_name = top->sub_name;
+ cpu_arch_flags = top->flags;
+ cpu_arch_isa = top->isa;
+ cpu_arch_isa_flags = top->isa_flags;
+ no_cond_jump_promotion = top->no_cond_jump_promotion;
+
+ XDELETE (top);
+ }
+
+ (void) restore_line_pointer (e);
+ demand_empty_rest_of_line ();
+ return;
+ }
for (; j < ARRAY_SIZE (cpu_arch); j++)
{
@@ -13685,6 +13760,10 @@ show_arch (FILE *stream, int ext, int ch
{
p = output_message (stream, p, message, start, &left,
STRING_COMMA_LEN ("default"));
+ p = output_message (stream, p, message, start, &left,
+ STRING_COMMA_LEN ("push"));
+ p = output_message (stream, p, message, start, &left,
+ STRING_COMMA_LEN ("pop"));
}
for (j = 0; j < ARRAY_SIZE (cpu_arch); j++)
--- a/gas/doc/c-i386.texi
+++ b/gas/doc/c-i386.texi
@@ -1504,7 +1504,7 @@ directive enables a warning when gas det
supported on the CPU specified. The choices for @var{cpu_type} are:
@multitable @columnfractions .20 .20 .20 .20
-@item @samp{default}
+@item @samp{default} @tab @samp{push} @tab @samp{pop}
@item @samp{i8086} @tab @samp{i186} @tab @samp{i286} @tab @samp{i386}
@item @samp{i486} @tab @samp{i586} @tab @samp{i686} @tab @samp{pentium}
@item @samp{pentiumpro} @tab @samp{pentiumii} @tab @samp{pentiumiii} @tab @samp{pentium4}
--- /dev/null
+++ b/gas/testsuite/gas/i386/arch-stk.l
@@ -0,0 +1,43 @@
+.*: Assembler messages:
+.*:3: Error:.*`cmovl'.*
+.*:10: Error:.*`cmovg'.*
+.*:17: Error:.*`cmovz'.*
+.*:21: Error:.*`\.arch pop'.*`\.code32'.*
+.*:28: Error:.*`\.arch pop'.*`\.code16gcc'.*
+.*:32: Error:.*\.arch.*empty.*
+GAS LISTING .*
+
+
+[ ]*[0-9]*[ ]+\.text
+[ ]*[0-9]*[ ]+start:
+[ ]*[0-9]*[ ]+cmovl %eax, %ecx
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch push
+[ ]*[0-9]*[ ]+\.arch default
+[ ]*[0-9]*[ ]+\?\?\?\? 0F4DC8[ ]+cmovnl %eax, %ecx
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]+cmovg %eax, %ecx
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch push
+[ ]*[0-9]*[ ]+\.arch \.cmov
+[ ]*[0-9]*[ ]+\?\?\?\? 0F4EC8[ ]+cmovng %eax, %ecx
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]+cmovz %eax, %ecx
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch push
+[ ]*[0-9]*[ ]+\.code16
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]+\.code32
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.code16gcc
+[ ]*[0-9]*[ ]+\.arch push
+[ ]*[0-9]*[ ]+\.code32
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]+\.code16gcc
+[ ]*[0-9]*[ ]+\.arch pop
+[ ]*[0-9]*[ ]*
+[ ]*[0-9]*[ ]+\.arch pop
+#pass
--- /dev/null
+++ b/gas/testsuite/gas/i386/arch-stk.s
@@ -0,0 +1,34 @@
+ .text
+start:
+ cmovl %eax, %ecx
+
+ .arch push
+ .arch default
+ cmovnl %eax, %ecx
+
+ .arch pop
+ cmovg %eax, %ecx
+
+ .arch push
+ .arch .cmov
+ cmovng %eax, %ecx
+
+ .arch pop
+ cmovz %eax, %ecx
+
+ .arch push
+ .code16
+ .arch pop
+ .code32
+ .arch pop
+
+ .code16gcc
+ .arch push
+ .code32
+ .arch pop
+ .code16gcc
+ .arch pop
+
+ .arch pop
+
+ .end
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -206,6 +206,7 @@ if [gas_32_check] then {
run_dump_test "arch-13"
run_dump_test "arch-14"
run_list_test "arch-dflt" "-march=generic32 -al"
+ run_list_test "arch-stk" "-march=generic32 -al"
run_dump_test "8087"
run_dump_test "287"
run_dump_test "387"
next prev parent reply other threads:[~2022-06-30 12:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-30 12:52 [PATCH] gas/x86: .arch / -march= enhancements Jan Beulich
2022-06-30 12:53 ` [PATCH 1/7] x86: don't leak sub-architecture accumulated strings Jan Beulich
2022-06-30 22:54 ` H.J. Lu
2022-07-01 10:18 ` Jan Beulich
2022-07-01 19:44 ` H.J. Lu
2022-06-30 12:53 ` [PATCH 2/7] x86: de-duplicate sub-architecture strings accumulation Jan Beulich
2022-06-30 22:55 ` H.J. Lu
2022-06-30 12:53 ` [PATCH 3/7] x86: permit "default" with .arch Jan Beulich
2022-06-30 22:58 ` H.J. Lu
2022-06-30 12:54 ` [PATCH 4/7] x86: macro-ize cpu_arch[] entries Jan Beulich
2022-06-30 23:00 ` H.J. Lu
2022-06-30 12:54 ` [PATCH 5/7] x86: introduce fake processor type to mark sub-arch entries in cpu_arch[] Jan Beulich
2022-06-30 23:03 ` H.J. Lu
2022-06-30 12:55 ` [PATCH 6/7] x86: generalize disabling of sub-architectures Jan Beulich
2022-06-30 23:11 ` H.J. Lu
2022-06-30 12:55 ` Jan Beulich [this message]
2022-06-30 23:15 ` [PATCH 7/7] x86: introduce a state stack for .arch H.J. Lu
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