[gcc r14-6996] amdgcn: Don't double-count AVGPRs

[Andrew Stubbs]

https://gcc.gnu.org/g:c5c3aab38132ea34dc1ee69d93fded787e6ac7a4

commit r14-6996-gc5c3aab38132ea34dc1ee69d93fded787e6ac7a4
Author: Andrew Stubbs <ams@codesourcery.com>
Date:   Wed Jan 3 16:18:43 2024 +0000

    amdgcn: Don't double-count AVGPRs
    
    CDNA2 devices have VGPRs and AVGPRs combined into a single hardware register
    file (they're seperate in CDNA1).  I originally thought they were counted
    separately in the vgpr_count and agpr_count metadata fields, and therefore
    mkoffload had to account for this when passing the values to libgomp.  However,
    that wasn't the case, and this code should have been removed when I corrected
    the calculations in gcn.cc.  Fixing the error now.
    
    gcc/ChangeLog:
    
            * config/gcn/mkoffload.cc (isa_has_combined_avgprs): Delete.
            (process_asm): Don't count avgprs.

Diff:
---
 gcc/config/gcn/mkoffload.cc | 29 -----------------------------
 1 file changed, 29 deletions(-)

diff --git a/gcc/config/gcn/mkoffload.cc b/gcc/config/gcn/mkoffload.cc
index 3341c0d34eb..03cd040dbd2 100644
--- a/gcc/config/gcn/mkoffload.cc
+++ b/gcc/config/gcn/mkoffload.cc
@@ -471,26 +471,6 @@ copy_early_debug_info (const char *infile, const char *outfile)
   return true;
 }
 
-/* CDNA2 devices have twice as many VGPRs compared to older devices,
-   but the AVGPRS are allocated from the same pool.  */
-
-static int
-isa_has_combined_avgprs (int isa)
-{
-  switch (isa)
-    {
-    case EF_AMDGPU_MACH_AMDGCN_GFX803:
-    case EF_AMDGPU_MACH_AMDGCN_GFX900:
-    case EF_AMDGPU_MACH_AMDGCN_GFX906:
-    case EF_AMDGPU_MACH_AMDGCN_GFX908:
-    case EF_AMDGPU_MACH_AMDGCN_GFX1030:
-      return false;
-    case EF_AMDGPU_MACH_AMDGCN_GFX90a:
-      return true;
-    }
-  fatal_error (input_location, "unhandled ISA in isa_has_combined_avgprs");
-}
-
 /* Parse an input assembler file, extract the offload tables etc.,
    and output (1) the assembler code, minus the tables (which can contain
    problematic relocations), and (2) a C file with the offload tables
@@ -516,7 +496,6 @@ process_asm (FILE *in, FILE *out, FILE *cfile)
   {
     int sgpr_count;
     int vgpr_count;
-    int avgpr_count;
     char *kernel_name;
   } regcount = { -1, -1, NULL };
 
@@ -564,12 +543,6 @@ process_asm (FILE *in, FILE *out, FILE *cfile)
 		gcc_assert (regcount.kernel_name);
 		break;
 	      }
-	    else if (sscanf (buf, " .agpr_count: %d\n",
-			     &regcount.avgpr_count) == 1)
-	      {
-		gcc_assert (regcount.kernel_name);
-		break;
-	      }
 
 	    break;
 	  }
@@ -712,8 +685,6 @@ process_asm (FILE *in, FILE *out, FILE *cfile)
 	  {
 	    sgpr_count = regcounts[j].sgpr_count;
 	    vgpr_count = regcounts[j].vgpr_count;
-	    if (isa_has_combined_avgprs (elf_arch))
-	      vgpr_count += regcounts[j].avgpr_count;
 	    break;
 	  }