[PATCH] x86: Add target("general-regs-only") function attribute

H.J. Lu hjl.tools@gmail.com
Sun Aug 23 15:07:03 GMT 2020


On Sun, Aug 23, 2020 at 10:18:28AM +0200, Uros Bizjak wrote:
> On Sat, Aug 22, 2020 at 9:09 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> 
> > > > Compile CPUID check with "-mno-sse -mfpmath=387" to disable SSE, AVX and
> > > > AVX512 during CPUID check to avoid vector and mask register operations.
> > >
> > > -mgeneral-regs-only ?
> > >
> >
> > Here is a patch to add target("general-regs-only") function
> > attribute and use it for CPUID check.   OK for master if there
> > are no regressions?
> 
> Please test it first, then ask for an approval.
> 
> Please submit the general-regs-only part as an independent patch. (I
> think this is the option linux should use for compilation).
> 

Tested on Linux/x86-64.  OK for master?

Thanks.

H.J.
---
gcc/

	PR target/96744
	* config/i386/i386-options.c (IX86_ATTR_IX86_YES): New.
	(IX86_ATTR_IX86_NO): Likewise.
	(ix86_opt_type): Add ix86_opt_ix86_yes and ix86_opt_ix86_no.
	(ix86_valid_target_attribute_inner_p): Handle general-regs-only,
	ix86_opt_ix86_yes and ix86_opt_ix86_no.
	(ix86_option_override_internal): Check opts->x_ix86_target_flags
	instead of opts->x_ix86_target_flags.
	* doc/extend.texi: Document target("general-regs-only") function
	attribute.

gcc/testsuite/

	PR target/96744
	* gcc.target/i386/pr96744-1.c: New test.
	* gcc.target/i386/pr96744-2.c: Likewise.
	* gcc.target/i386/pr96744-3a.c: Likewise.
	* gcc.target/i386/pr96744-3b.c: Likewise.
	* gcc.target/i386/pr96744-4.c: Likewise.
	* gcc.target/i386/pr96744-5.c: Likewise.
	* gcc.target/i386/pr96744-6.c: Likewise.
	* gcc.target/i386/pr96744-7.c: Likewise.
	* gcc.target/i386/pr96744-8a.c: Likewise.
	* gcc.target/i386/pr96744-8b.c: Likewise.
	* gcc.target/i386/pr96744-9.c: Likewise.
---
 gcc/config/i386/i386-options.c             | 44 ++++++++++++++++++++--
 gcc/doc/extend.texi                        |  4 ++
 gcc/testsuite/gcc.target/i386/pr96744-1.c  | 10 +++++
 gcc/testsuite/gcc.target/i386/pr96744-2.c  | 11 ++++++
 gcc/testsuite/gcc.target/i386/pr96744-3a.c | 12 ++++++
 gcc/testsuite/gcc.target/i386/pr96744-3b.c | 16 ++++++++
 gcc/testsuite/gcc.target/i386/pr96744-4.c  | 11 ++++++
 gcc/testsuite/gcc.target/i386/pr96744-5.c  | 17 +++++++++
 gcc/testsuite/gcc.target/i386/pr96744-6.c  | 11 ++++++
 gcc/testsuite/gcc.target/i386/pr96744-7.c  | 14 +++++++
 gcc/testsuite/gcc.target/i386/pr96744-8a.c | 33 ++++++++++++++++
 gcc/testsuite/gcc.target/i386/pr96744-8b.c | 35 +++++++++++++++++
 gcc/testsuite/gcc.target/i386/pr96744-9.c  | 25 ++++++++++++
 13 files changed, 240 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-3a.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-3b.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-5.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-6.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-7.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-8a.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-8b.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr96744-9.c

diff --git a/gcc/config/i386/i386-options.c b/gcc/config/i386/i386-options.c
index 26d1ea18ef1..e0fc68c27bf 100644
--- a/gcc/config/i386/i386-options.c
+++ b/gcc/config/i386/i386-options.c
@@ -922,12 +922,18 @@ ix86_valid_target_attribute_inner_p (tree fndecl, tree args, char *p_strings[],
 #define IX86_ATTR_ENUM(S,O)  { S, sizeof (S)-1, ix86_opt_enum, O, 0 }
 #define IX86_ATTR_YES(S,O,M) { S, sizeof (S)-1, ix86_opt_yes, O, M }
 #define IX86_ATTR_NO(S,O,M)  { S, sizeof (S)-1, ix86_opt_no,  O, M }
+#define IX86_ATTR_IX86_YES(S,O,M) \
+  { S, sizeof (S)-1, ix86_opt_ix86_yes, O, M }
+#define IX86_ATTR_IX86_NO(S,O,M) \
+  { S, sizeof (S)-1, ix86_opt_ix86_no,  O, M }
 
   enum ix86_opt_type
   {
     ix86_opt_unknown,
     ix86_opt_yes,
     ix86_opt_no,
+    ix86_opt_ix86_yes,
+    ix86_opt_ix86_no,
     ix86_opt_str,
     ix86_opt_enum,
     ix86_opt_isa
@@ -1062,6 +1068,10 @@ ix86_valid_target_attribute_inner_p (tree fndecl, tree args, char *p_strings[],
     IX86_ATTR_YES ("recip",
 		   OPT_mrecip,
 		   MASK_RECIP),
+
+    IX86_ATTR_IX86_YES ("general-regs-only",
+			OPT_mgeneral_regs_only,
+			OPTION_MASK_GENERAL_REGS_ONLY),
   };
 
   location_t loc
@@ -1175,6 +1185,33 @@ ix86_valid_target_attribute_inner_p (tree fndecl, tree args, char *p_strings[],
 	    opts->x_target_flags &= ~mask;
 	}
 
+      else if (type == ix86_opt_ix86_yes || type == ix86_opt_ix86_no)
+	{
+	  if (mask == OPTION_MASK_GENERAL_REGS_ONLY)
+	    {
+	      if (type != ix86_opt_ix86_yes)
+		gcc_unreachable ();
+
+	      opts->x_ix86_target_flags |= mask;
+
+	      struct cl_decoded_option decoded;
+	      generate_option (opt, NULL, opt_set_p, CL_TARGET,
+			       &decoded);
+	      ix86_handle_option (opts, opts_set, &decoded,
+				  input_location);
+	    }
+	  else
+	    {
+	      if (type == ix86_opt_ix86_no)
+		opt_set_p = !opt_set_p;
+
+	      if (opt_set_p)
+		opts->x_ix86_target_flags |= mask;
+	      else
+		opts->x_ix86_target_flags &= ~mask;
+	    }
+	}
+
       else if (type == ix86_opt_str)
 	{
 	  if (p_strings[opt])
@@ -2260,9 +2297,10 @@ ix86_option_override_internal (bool main_args_p,
 	    && !(opts->x_ix86_isa_flags_explicit & OPTION_MASK_ISA_PKU))
 	  opts->x_ix86_isa_flags |= OPTION_MASK_ISA_PKU;
 
-	/* Don't enable x87 instructions if only
-	   general registers are allowed.  */
-	if (!(opts_set->x_ix86_target_flags & OPTION_MASK_GENERAL_REGS_ONLY)
+	/* Don't enable x87 instructions if only general registers are
+	   allowed by target("general-regs-only") function attribute or
+	   -mgeneral-regs-only.  */
+	if (!(opts->x_ix86_target_flags & OPTION_MASK_GENERAL_REGS_ONLY)
 	    && !(opts_set->x_target_flags & MASK_80387))
 	  {
 	    if (((processor_alias_table[i].flags & PTA_NO_80387) != 0))
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index fd794961e0a..2bb9b2f72f5 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -6656,6 +6656,10 @@ Enable/disable the generation of RCPSS, RCPPS, RSQRTSS and RSQRTPS
 instructions followed an additional Newton-Raphson step instead of
 doing a floating-point division.
 
+@item general-regs-only
+@cindex @code{target("general-regs-only")} function attribute, x86
+Generate code which uses only the general registers.
+
 @item arch=@var{ARCH}
 @cindex @code{target("arch=@var{ARCH}")} function attribute, x86
 Specify the architecture to generate code for in compiling the function.
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-1.c b/gcc/testsuite/gcc.target/i386/pr96744-1.c
new file mode 100644
index 00000000000..46f3ce6ddd4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-msse2" } */
+
+typedef int int32x2_t __attribute__ ((__vector_size__ ((8))));
+
+__attribute__((__target__("general-regs-only")))
+int32x2_t test (int32x2_t a, int32x2_t b)
+{ /* { dg-error "SSE register return with SSE disabled" } */
+  return a + b;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-2.c b/gcc/testsuite/gcc.target/i386/pr96744-2.c
new file mode 100644
index 00000000000..4a436d8ef04
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-2.c
@@ -0,0 +1,11 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-mmmx" } */
+
+typedef int int32x2_t __attribute__ ((__vector_size__ ((8))));
+
+__attribute__((__target__("general-regs-only")))
+int32x2_t
+test (int32x2_t a, int32x2_t b) /* { dg-warning "MMX vector argument without MMX enabled" } */
+{ /* { dg-warning "MMX vector return without MMX enabled" } */
+  return a + b;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-3a.c b/gcc/testsuite/gcc.target/i386/pr96744-3a.c
new file mode 100644
index 00000000000..79191544eb4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-3a.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-msse2" } */
+
+typedef int int32x4_t __attribute__ ((__vector_size__ ((16))));
+extern int32x4_t c;
+
+__attribute__((__target__("general-regs-only")))
+void
+test (int32x4_t a, int32x4_t b) /* { dg-warning "SSE vector argument without SSE enabled" } */
+{
+  c = a + b;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-3b.c b/gcc/testsuite/gcc.target/i386/pr96744-3b.c
new file mode 100644
index 00000000000..389b5cf9897
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-3b.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-msse2" } */
+
+typedef int int32x4_t __attribute__ ((__vector_size__ ((16))));
+extern int32x4_t c;
+
+#pragma GCC push_options
+#pragma GCC target("general-regs-only")
+
+void
+test (int32x4_t a, int32x4_t b) /* { dg-warning "SSE vector argument without SSE enabled" } */
+{
+  c = a + b;
+}
+
+#pragma GCC pop_options
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-4.c b/gcc/testsuite/gcc.target/i386/pr96744-4.c
new file mode 100644
index 00000000000..005329f95e9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-4.c
@@ -0,0 +1,11 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-msse2" } */
+
+typedef int int32x4_t __attribute__ ((__vector_size__ ((16))));
+
+__attribute__((__target__("general-regs-only")))
+int32x4_t
+test (int32x4_t a, int32x4_t b) /* { dg-warning "SSE vector argument without SSE enabled" } */
+{ /* { dg-warning "SSE vector return without SSE enabled" } */
+  return a + b;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-5.c b/gcc/testsuite/gcc.target/i386/pr96744-5.c
new file mode 100644
index 00000000000..18f2132aa27
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-5.c
@@ -0,0 +1,17 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-msse2" } */
+
+#include <stdarg.h>
+
+typedef int int32x2_t __attribute__ ((__vector_size__ ((8))));
+
+__attribute__((__target__("general-regs-only")))
+int
+test (int i, ...)
+{
+  va_list argp;
+  va_start (argp, i);
+  int32x2_t x = (int32x2_t) {0, 1};
+  x += va_arg (argp, int32x2_t); /* { dg-error "SSE register argument with SSE disabled" } */
+  return x[0] + x[1];
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-6.c b/gcc/testsuite/gcc.target/i386/pr96744-6.c
new file mode 100644
index 00000000000..38a3cc7fa92
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-6.c
@@ -0,0 +1,11 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-msse2 -mfpmath=sse" } */
+
+extern float a, b, c;
+
+__attribute__((__target__("general-regs-only")))
+void
+foo (void)
+{
+  c = a * b; /* { dg-error "SSE register return with SSE disabled" } */
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-7.c b/gcc/testsuite/gcc.target/i386/pr96744-7.c
new file mode 100644
index 00000000000..5f55b6cbd33
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-7.c
@@ -0,0 +1,14 @@
+/* { dg-do compile { target { ia32 && { ! *-*-darwin* } } } } */
+/* { dg-options "-msse2" } */
+
+extern float a, b, c;
+
+__attribute__((__target__("general-regs-only")))
+void
+foo (void)
+{
+  c = a * b;
+}
+
+/* { dg-final { scan-assembler-not "mulss" } } */
+/* { dg-final { scan-assembler "call\[ \t\]__mulsf3" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-8a.c b/gcc/testsuite/gcc.target/i386/pr96744-8a.c
new file mode 100644
index 00000000000..d264e1e01d4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-8a.c
@@ -0,0 +1,33 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort ();
+
+__attribute__((__target__("general-regs-only")))
+int
+dec (int a, int b)
+{
+  return a + b;
+}
+
+__attribute__((__target__("general-regs-only")))
+int
+cal (int a, int b)
+{
+  int sum1 = a * b;
+  int sum2 = a / b;
+  int sum = dec (sum1, sum2);
+  return a + b + sum + sum1 + sum2;
+}
+
+__attribute__((__target__("general-regs-only")))
+int
+main (int argc, char **argv)
+{
+  int ret = cal (2, 1);
+
+  if (ret != 11)
+    abort ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-8b.c b/gcc/testsuite/gcc.target/i386/pr96744-8b.c
new file mode 100644
index 00000000000..30e763d932e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-8b.c
@@ -0,0 +1,35 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+#pragma GCC push_options
+#pragma GCC target("general-regs-only")
+
+extern void abort ();
+
+int
+dec (int a, int b)
+{
+  return a + b;
+}
+
+int
+cal (int a, int b)
+{
+  int sum1 = a * b;
+  int sum2 = a / b;
+  int sum = dec (sum1, sum2);
+  return a + b + sum + sum1 + sum2;
+}
+
+int
+main (int argc, char **argv)
+{
+  int ret = cal (2, 1);
+
+  if (ret != 11)
+    abort ();
+
+  return 0;
+}
+
+#pragma GCC pop_options
diff --git a/gcc/testsuite/gcc.target/i386/pr96744-9.c b/gcc/testsuite/gcc.target/i386/pr96744-9.c
new file mode 100644
index 00000000000..196e86f08e9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr96744-9.c
@@ -0,0 +1,25 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort ();
+
+__attribute__((__target__("general-regs-only")))
+int
+cal (int a, int b)
+{
+  int sum = a + b;
+  int sum1 = a * b;
+  return (a + b + sum + sum1);
+}
+
+__attribute__((__target__("general-regs-only")))
+int
+main (int argc, char **argv)
+{
+  int ret = cal (1, 2);
+
+  if (ret != 8)
+    abort ();
+
+  return 0;
+}
-- 
2.26.2



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