[compiler-rt] [llvm] [compiler-rt][X86] Unify getAMDProcessorTypeAndSubType (PR #97863)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/97863

This patch unifies the implementation of getAMDProcessorTypeAndSubtype between compiler-rt and LLVM.

This patch is intended to be a step towards pulling these functions out into identical .inc files to better facilitate code sharing between LLVM and compiler-rt.

>From 2be7a7864cedafd42f9ca0aee35d6a7695899243 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Fri, 5 Jul 2024 22:02:44 +0000
Subject: [PATCH] [compiler-rt][X86] Unify getAMDProcessorTypeAndSubType

This patch unifies the implementation of getAMDProcessorTypeAndSubtype
between compiler-rt and LLVM.

This patch is intended to be a step towards pulling these functions out
into identical .inc files to better facilitate code sharing between LLVM
and compiler-rt.
---
 compiler-rt/lib/builtins/cpu_model/x86.c | 42 +++++++++++++++++++++---
 llvm/lib/TargetParser/Host.cpp           | 21 +++++-------
 2 files changed, 46 insertions(+), 17 deletions(-)

diff --git a/compiler-rt/lib/builtins/cpu_model/x86.c b/compiler-rt/lib/builtins/cpu_model/x86.c
index 7e8acb3e73eda..546976d83c3a7 100644
--- a/compiler-rt/lib/builtins/cpu_model/x86.c
+++ b/compiler-rt/lib/builtins/cpu_model/x86.c
@@ -662,14 +662,48 @@ static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
                                                  const unsigned *Features,
                                                  unsigned *Type,
                                                  unsigned *Subtype) {
-  // We select CPU strings to match the code in Host.cpp, but we don't use them
-  // in compiler-rt.
   const char *CPU = 0;
 
   switch (Family) {
+  case 4:
+    CPU = "i486";
+    break;
+  case 5:
+    CPU = "pentium";
+    switch (Model) {
+    case 6:
+    case 7:
+      CPU = "k6";
+      break;
+    case 8:
+      CPU = "k6-2";
+      break;
+    case 9:
+    case 13:
+      CPU = "k6-3";
+      break;
+    case 10:
+      CPU = "geode";
+      break;
+    }
+    break;
+  case 6:
+    if (testFeature(FEATURE_SSE)) {
+      CPU = "athlon-xp";
+      break;
+    }
+    CPU = "athlon";
+    break;
+  case 15:
+    if (testFeature(FEATURE_SSE3)) {
+      CPU = "k8-sse3";
+      break;
+    }
+    CPU = "k8";
+    break;
   case 16:
     CPU = "amdfam10";
-    *Type = AMDFAM10H;
+    *Type = AMDFAM10H; // "amdfam10"
     switch (Model) {
     case 2:
       *Subtype = AMDFAM10H_BARCELONA;
@@ -745,7 +779,7 @@ static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
   case 25:
     CPU = "znver3";
     *Type = AMDFAM19H;
-    if ((Model <= 0x0f) || (Model >= 0x20 && Model <= 0x2f) ||
+    if (Model <= 0x0f || (Model >= 0x20 && Model <= 0x2f) ||
         (Model >= 0x30 && Model <= 0x3f) || (Model >= 0x40 && Model <= 0x4f) ||
         (Model >= 0x50 && Model <= 0x5f)) {
       // Family 19h Models 00h-0Fh (Genesis, Chagall) Zen 3
diff --git a/llvm/lib/TargetParser/Host.cpp b/llvm/lib/TargetParser/Host.cpp
index 2ea56746aff24..90b7d7672e931 100644
--- a/llvm/lib/TargetParser/Host.cpp
+++ b/llvm/lib/TargetParser/Host.cpp
@@ -707,9 +707,7 @@ static StringRef
 getIntelProcessorTypeAndSubtype(unsigned Family, unsigned Model,
                                 const unsigned *Features,
                                 unsigned *Type, unsigned *Subtype) {
-  auto testFeature = [&](unsigned F) {
-    return (Features[F / 32] & (1U << (F % 32))) != 0;
-  };
+#define testFeature(F) (Features[F / 32] & (1 << (F % 32))) != 0
 
   StringRef CPU;
 
@@ -1067,15 +1065,12 @@ getIntelProcessorTypeAndSubtype(unsigned Family, unsigned Model,
   return CPU;
 }
 
-static StringRef
-getAMDProcessorTypeAndSubtype(unsigned Family, unsigned Model,
-                              const unsigned *Features,
-                              unsigned *Type, unsigned *Subtype) {
-  auto testFeature = [&](unsigned F) {
-    return (Features[F / 32] & (1U << (F % 32))) != 0;
-  };
-
-  StringRef CPU;
+static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
+                                                 unsigned Model,
+                                                 const unsigned *Features,
+                                                 unsigned *Type,
+                                                 unsigned *Subtype) {
+  const char *CPU = 0;
 
   switch (Family) {
   case 4:
@@ -1215,7 +1210,7 @@ getAMDProcessorTypeAndSubtype(unsigned Family, unsigned Model,
       *Subtype = X86::AMDFAM19H_ZNVER4;
       break; //  "znver4"
     }
-    break;
+    break; // family 19h
   default:
     break; // Unknown AMD CPU.
   }