Hello,

> -----Original Message-----
> From: Martin Jambor <[email protected]>
> Sent: Monday, September 29, 2025 5:16 PM
> To: Kalvakuntla, Umesh <[email protected]>; gcc-
> [email protected]
> Cc: Gopalasubramanian, Ganesh <[email protected]>; Jan
> Hubicka <[email protected]>
> Subject: RE: [PATCH] [X86] Fixes for AMD znver5 enablement
> 
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
> 
> 
> Hello,
> 
> On Fri, Sep 26 2025, Kalvakuntla, Umesh wrote:
> > [AMD Official Use Only - AMD Internal Distribution Only]
> >
> > Hello Martin,
> >
> > Can you please commit this? I don't have the required rights.
> 
> Honza is in favor, so I think I can.  Can you please write the corresponding
> ChangeLog and provide information how the patch has been tested?

Tested the patch with below command on znver5 machine:
$ gcc -Q -march=native --help=target | grep prefetchi
 -mprefetchi                           [enabled]

Model numbers are updated as per specification.

Updated patch with Changelog :

---
 gcc/ChangeLog                    |  7 +++++++
 gcc/common/config/i386/cpuinfo.h | 12 +++++++++++-
 gcc/config/i386/cpuid.h          |  4 ++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 63fd0f27d03..60a8a1af697 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2025-09-29  Umesh Kalvakuntla <[email protected]>
+
+       * common/config/i386/cpuinfo.h (get_amd_cpu): 
+       Fix znver5 family model numbers.
+       (get_available_features): Set FEATURE_PREFETCHI for bit_AMD_PREFETCHI.
+       * config/i386/cpuid.h (bit_AMD_PREFETCHI): New Macro.
+
 2025-09-28  liuhongt  <[email protected]>
 
        PR target/121970
diff --git a/gcc/common/config/i386/cpuinfo.h b/gcc/common/config/i386/cpuinfo.h
index c93ea07239a..3f29f17e2a5 100644
--- a/gcc/common/config/i386/cpuinfo.h
+++ b/gcc/common/config/i386/cpuinfo.h
@@ -312,7 +312,8 @@ get_amd_cpu (struct __processor_model *cpu_model,
       break;
     case 0x1a:
       cpu_model->__cpu_type = AMDFAM1AH;
-      if (model <= 0x77)
+      if (model <= 0x4f || (model >= 0x60 && model <= 0x77) ||
+         (model >= 0xd0 && model <= 0xd7))
        {
          cpu = "znver5";
          CHECK___builtin_cpu_is ("znver5");
@@ -1102,6 +1103,15 @@ get_available_features (struct __processor_model 
*cpu_model,
        set_feature (FEATURE_WBNOINVD);
     }
 
+  if (ext_level >= 0x80000021)
+    {
+      __cpuid (0x80000021, eax, ebx, ecx, edx);
+      if (eax & bit_AMD_PREFETCHI)
+       {
+         set_feature (FEATURE_PREFETCHI);
+       }
+    }
+
 #undef set_feature
 }
 
diff --git a/gcc/config/i386/cpuid.h b/gcc/config/i386/cpuid.h
index afd4ef06e9f..dac01d887f1 100644
--- a/gcc/config/i386/cpuid.h
+++ b/gcc/config/i386/cpuid.h
@@ -72,6 +72,10 @@
 #define bit_CLZERO     (1 << 0)
 #define bit_WBNOINVD   (1 << 9)
 
+/* Extended Features (%eax == 0x80000021) */
+/* %eax */
+#define bit_AMD_PREFETCHI (1 << 20) 
+
 /* Extended Features Leaf (%eax == 7, %ecx == 0) */
 /* %ebx */
 #define bit_FSGSBASE   (1 << 0)
-- 
2.43.0



Thanks,
Umesh


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