[llvm-branch-commits] [llvm] 045d84f - D94954: Fixes Snapdragon Kryo CPU core detection

David Green via llvm-branch-commits llvm-branch-commits at lists.llvm.org
Wed Jan 20 14:28:42 PST 2021


Author: Ryan Houdek
Date: 2021-01-20T22:23:43Z
New Revision: 045d84f4e6d7d6bbccaa6d965669a068fc329809

URL: https://github.com/llvm/llvm-project/commit/045d84f4e6d7d6bbccaa6d965669a068fc329809
DIFF: https://github.com/llvm/llvm-project/commit/045d84f4e6d7d6bbccaa6d965669a068fc329809.diff

LOG: D94954: Fixes Snapdragon Kryo CPU core detection

All of these families were claiming to be a73 based, which was causing
-mcpu/mtune=native to never use the newer features available to these
cores.

Goes through each and bumps the individual cores to their respective Big
counterparts. Since this code path doesn't support big.little detection,
there was already a precedent set with the Qualcomm line to choose the
big cores only.

Adds a comment on each line for the product's name that the part number
refers to. Confirmed on-device and through Linux header naming
convections.

Additionally newer SoCs mix CPU implementer parts from multiple
implementers. Both 0x41 (ARM) and 0x51 (Qualcomm) in the Snapdragon case

This was causing a desync in information where the scan at the start to
find the implementer would mismatch the part scan later on.
Now scan for both implementer and part at the start so these stay in
sync.

Differential Revision: https://reviews.llvm.org/D94954

Added: 
    

Modified: 
    llvm/lib/Support/Host.cpp
    llvm/unittests/Support/Host.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp
index ea561abb28878..a1bd3cc12f1d1 100644
--- a/llvm/lib/Support/Host.cpp
+++ b/llvm/lib/Support/Host.cpp
@@ -161,11 +161,14 @@ StringRef sys::detail::getHostCPUNameForARM(StringRef ProcCpuinfoContent) {
   // Look for the CPU implementer line.
   StringRef Implementer;
   StringRef Hardware;
+  StringRef Part;
   for (unsigned I = 0, E = Lines.size(); I != E; ++I) {
     if (Lines[I].startswith("CPU implementer"))
       Implementer = Lines[I].substr(15).ltrim("\t :");
     if (Lines[I].startswith("Hardware"))
       Hardware = Lines[I].substr(8).ltrim("\t :");
+    if (Lines[I].startswith("CPU part"))
+      Part = Lines[I].substr(8).ltrim("\t :");
   }
 
   if (Implementer == "0x41") { // ARM Ltd.
@@ -175,111 +178,89 @@ StringRef sys::detail::getHostCPUNameForARM(StringRef ProcCpuinfoContent) {
       return "cortex-a53";
 
 
-    // Look for the CPU part line.
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I)
-      if (Lines[I].startswith("CPU part"))
-        // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
-        // values correspond to the "Part number" in the CP15/c0 register. The
-        // contents are specified in the various processor manuals.
-        // This corresponds to the Main ID Register in Technical Reference Manuals.
-        // and is used in programs like sys-utils
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-            .Case("0x926", "arm926ej-s")
-            .Case("0xb02", "mpcore")
-            .Case("0xb36", "arm1136j-s")
-            .Case("0xb56", "arm1156t2-s")
-            .Case("0xb76", "arm1176jz-s")
-            .Case("0xc08", "cortex-a8")
-            .Case("0xc09", "cortex-a9")
-            .Case("0xc0f", "cortex-a15")
-            .Case("0xc20", "cortex-m0")
-            .Case("0xc23", "cortex-m3")
-            .Case("0xc24", "cortex-m4")
-            .Case("0xd22", "cortex-m55")
-            .Case("0xd02", "cortex-a34")
-            .Case("0xd04", "cortex-a35")
-            .Case("0xd03", "cortex-a53")
-            .Case("0xd07", "cortex-a57")
-            .Case("0xd08", "cortex-a72")
-            .Case("0xd09", "cortex-a73")
-            .Case("0xd0a", "cortex-a75")
-            .Case("0xd0b", "cortex-a76")
-            .Case("0xd0d", "cortex-a77")
-            .Case("0xd41", "cortex-a78")
-            .Case("0xd44", "cortex-x1")
-            .Case("0xd0c", "neoverse-n1")
-            .Case("0xd49", "neoverse-n2")
-            .Default("generic");
+    // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
+    // values correspond to the "Part number" in the CP15/c0 register. The
+    // contents are specified in the various processor manuals.
+    // This corresponds to the Main ID Register in Technical Reference Manuals.
+    // and is used in programs like sys-utils
+    return StringSwitch<const char *>(Part)
+        .Case("0x926", "arm926ej-s")
+        .Case("0xb02", "mpcore")
+        .Case("0xb36", "arm1136j-s")
+        .Case("0xb56", "arm1156t2-s")
+        .Case("0xb76", "arm1176jz-s")
+        .Case("0xc08", "cortex-a8")
+        .Case("0xc09", "cortex-a9")
+        .Case("0xc0f", "cortex-a15")
+        .Case("0xc20", "cortex-m0")
+        .Case("0xc23", "cortex-m3")
+        .Case("0xc24", "cortex-m4")
+        .Case("0xd22", "cortex-m55")
+        .Case("0xd02", "cortex-a34")
+        .Case("0xd04", "cortex-a35")
+        .Case("0xd03", "cortex-a53")
+        .Case("0xd07", "cortex-a57")
+        .Case("0xd08", "cortex-a72")
+        .Case("0xd09", "cortex-a73")
+        .Case("0xd0a", "cortex-a75")
+        .Case("0xd0b", "cortex-a76")
+        .Case("0xd0d", "cortex-a77")
+        .Case("0xd41", "cortex-a78")
+        .Case("0xd44", "cortex-x1")
+        .Case("0xd0c", "neoverse-n1")
+        .Case("0xd49", "neoverse-n2")
+        .Default("generic");
   }
 
   if (Implementer == "0x42" || Implementer == "0x43") { // Broadcom | Cavium.
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I) {
-      if (Lines[I].startswith("CPU part")) {
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-          .Case("0x516", "thunderx2t99")
-          .Case("0x0516", "thunderx2t99")
-          .Case("0xaf", "thunderx2t99")
-          .Case("0x0af", "thunderx2t99")
-          .Case("0xa1", "thunderxt88")
-          .Case("0x0a1", "thunderxt88")
-          .Default("generic");
-      }
-    }
+    return StringSwitch<const char *>(Part)
+      .Case("0x516", "thunderx2t99")
+      .Case("0x0516", "thunderx2t99")
+      .Case("0xaf", "thunderx2t99")
+      .Case("0x0af", "thunderx2t99")
+      .Case("0xa1", "thunderxt88")
+      .Case("0x0a1", "thunderxt88")
+      .Default("generic");
   }
 
   if (Implementer == "0x46") { // Fujitsu Ltd.
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I) {
-      if (Lines[I].startswith("CPU part")) {
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-          .Case("0x001", "a64fx")
-          .Default("generic");
-      }
-    }
+    return StringSwitch<const char *>(Part)
+      .Case("0x001", "a64fx")
+      .Default("generic");
   }
 
   if (Implementer == "0x4e") { // NVIDIA Corporation
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I) {
-      if (Lines[I].startswith("CPU part")) {
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-            .Case("0x004", "carmel")
-            .Default("generic");
-      }
-    }
+    return StringSwitch<const char *>(Part)
+        .Case("0x004", "carmel")
+        .Default("generic");
   }
 
   if (Implementer == "0x48") // HiSilicon Technologies, Inc.
-    // Look for the CPU part line.
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I)
-      if (Lines[I].startswith("CPU part"))
-        // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
-        // values correspond to the "Part number" in the CP15/c0 register. The
-        // contents are specified in the various processor manuals.
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-          .Case("0xd01", "tsv110")
-          .Default("generic");
+    // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
+    // values correspond to the "Part number" in the CP15/c0 register. The
+    // contents are specified in the various processor manuals.
+    return StringSwitch<const char *>(Part)
+      .Case("0xd01", "tsv110")
+      .Default("generic");
 
   if (Implementer == "0x51") // Qualcomm Technologies, Inc.
-    // Look for the CPU part line.
-    for (unsigned I = 0, E = Lines.size(); I != E; ++I)
-      if (Lines[I].startswith("CPU part"))
-        // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
-        // values correspond to the "Part number" in the CP15/c0 register. The
-        // contents are specified in the various processor manuals.
-        return StringSwitch<const char *>(Lines[I].substr(8).ltrim("\t :"))
-            .Case("0x06f", "krait") // APQ8064
-            .Case("0x201", "kryo")
-            .Case("0x205", "kryo")
-            .Case("0x211", "kryo")
-            .Case("0x800", "cortex-a73")
-            .Case("0x801", "cortex-a73")
-            .Case("0x802", "cortex-a73")
-            .Case("0x803", "cortex-a73")
-            .Case("0x804", "cortex-a73")
-            .Case("0x805", "cortex-a73")
-            .Case("0xc00", "falkor")
-            .Case("0xc01", "saphira")
-            .Default("generic");
-
+    // The CPU part is a 3 digit hexadecimal number with a 0x prefix. The
+    // values correspond to the "Part number" in the CP15/c0 register. The
+    // contents are specified in the various processor manuals.
+    return StringSwitch<const char *>(Part)
+        .Case("0x06f", "krait") // APQ8064
+        .Case("0x201", "kryo")
+        .Case("0x205", "kryo")
+        .Case("0x211", "kryo")
+        .Case("0x800", "cortex-a73") // Kryo 2xx Gold
+        .Case("0x801", "cortex-a73") // Kryo 2xx Silver
+        .Case("0x802", "cortex-a75") // Kryo 3xx Gold
+        .Case("0x803", "cortex-a75") // Kryo 3xx Silver
+        .Case("0x804", "cortex-a76") // Kryo 4xx Gold
+        .Case("0x805", "cortex-a76") // Kryo 4xx/5xx Silver
+        .Case("0xc00", "falkor")
+        .Case("0xc01", "saphira")
+        .Default("generic");
   if (Implementer == "0x53") { // Samsung Electronics Co., Ltd.
     // The Exynos chips have a convoluted ID scheme that doesn't seem to follow
     // any predictive pattern across variants and parts.

diff  --git a/llvm/unittests/Support/Host.cpp b/llvm/unittests/Support/Host.cpp
index b452048361db6..c85fd996643bf 100644
--- a/llvm/unittests/Support/Host.cpp
+++ b/llvm/unittests/Support/Host.cpp
@@ -282,6 +282,32 @@ CPU revision    : 0
 )";
 
   EXPECT_EQ(sys::detail::getHostCPUNameForARM(CarmelProcCpuInfo), "carmel");
+
+  // Snapdragon mixed implementer quirk
+  const std::string Snapdragon865ProcCPUInfo = R"(
+processor       : 0
+BogoMIPS        : 38.40
+Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp asimdhp cpuid asimdrdm lrcpc dcpop asimddp
+CPU implementer : 0x51
+CPU architecture: 8
+CPU variant     : 0xd
+CPU part        : 0x805
+CPU revision    : 14
+processor       : 1
+processor       : 2
+processor       : 3
+processor       : 4
+processor       : 5
+processor       : 6
+BogoMIPS        : 38.40
+Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp asimdhp cpuid asimdrdm lrcpc dcpop asimddp
+CPU implementer : 0x41
+CPU architecture: 8
+CPU variant     : 0x1
+CPU part        : 0xd0d
+CPU revision    : 0
+)";
+  EXPECT_EQ(sys::detail::getHostCPUNameForARM(Snapdragon865ProcCPUInfo), "cortex-a77");
 }
 
 #if defined(__APPLE__) || defined(_AIX)


        


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