[gcc/devel/omp/gcc-12] amdgcn: Pass -mstack-size through to runtime

[Andrew Stubbs <ams@gcc.gnu.org>]

https://gcc.gnu.org/g:196b25d7b9b73fa89ffb2f6dc73b851584f81127

commit 196b25d7b9b73fa89ffb2f6dc73b851584f81127
Author: Andrew Stubbs <ams@codesourcery.com>
Date:   Mon Feb 6 12:47:28 2023 +0000

    amdgcn: Pass -mstack-size through to runtime
    
    But only for the offload case.
    
    gcc/ChangeLog:
    
            * config/gcn/mkoffload.cc (gcn_stack_size): New global variable.
            (process_asm): Create a constructor for GCN_STACK_SIZE.
            (main): Parse the -mstack-size option.
    
    (cherry picked from commit 45e01229af33a3dc3f124dcaec4b4ae11e9d07ce)

Diff:
---
 gcc/ChangeLog.omp           |  6 ++++++
 gcc/config/gcn/mkoffload.cc | 18 ++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index f7d0c439245..4205a15ef7b 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,3 +1,9 @@
+2023-02-06  Andrew Stubbs  <ams@codesourcery.com>
+
+	* config/gcn/mkoffload.cc (gcn_stack_size): New global variable.
+	(process_asm): Create a constructor for GCN_STACK_SIZE.
+	(main): Parse the -mstack-size option.
+
 2023-02-06  Andrew Stubbs  <ams@codesourcery.com>
 
 	* config/gcn/gcn-run.cc: Include libgomp-gcn.h.
diff --git a/gcc/config/gcn/mkoffload.cc b/gcc/config/gcn/mkoffload.cc
index 14d7eedc790..3af3f717ea6 100644
--- a/gcc/config/gcn/mkoffload.cc
+++ b/gcc/config/gcn/mkoffload.cc
@@ -123,6 +123,8 @@ uint32_t elf_arch = EF_AMDGPU_MACH_AMDGCN_GFX803;  // Default GPU architecture.
 uint32_t elf_flags =
     (EF_AMDGPU_FEATURE_XNACK_ANY_V4 | EF_AMDGPU_FEATURE_SRAMECC_ANY_V4);
 
+static int gcn_stack_size = 0;  /* Zero means use default.  */
+
 /* Delete tempfiles.  */
 
 void
@@ -701,6 +703,18 @@ process_asm (FILE *in, FILE *out, FILE *cfile)
 	      ? "val[0] != '1' || val[1] != '\\0'"
 	      : "val[0] == '1' && val[1] == '\\0'"));
 
+  /* Set the stack size if the user configured a value.  */
+  if (gcn_stack_size)
+    fprintf (cfile,
+	     "static __attribute__((constructor))\n"
+	     "void configure_stack_size (void)\n"
+	     "{\n"
+	     "  const char *val = getenv (\"GCN_STACK_SIZE\");\n"
+	     "  if (!val || val[0] == '\\0')\n"
+	     "    setenv (\"GCN_STACK_SIZE\", \"%d\", true);\n"
+	     "}\n\n",
+	     gcn_stack_size);
+
   obstack_free (&fns_os, NULL);
   for (i = 0; i < dims_count; i++)
     free (dims[i].name);
@@ -961,6 +975,10 @@ main (int argc, char **argv)
 	elf_arch = EF_AMDGPU_MACH_AMDGCN_GFX908;
       else if (strcmp (argv[i], "-march=gfx90a") == 0)
 	elf_arch = EF_AMDGPU_MACH_AMDGCN_GFX90a;
+#define STR "-mstack-size="
+      else if (startswith (argv[i], STR))
+	gcn_stack_size = atoi (argv[i] + strlen (STR));
+#undef STR
     }
 
   if (!(fopenacc ^ fopenmp))