[llvm] 993f38d - [SystemZ][z/OS] Implement getHostCPUName for z/OS
Anirudh Prasad via llvm-commits
llvm-commits at lists.llvm.org
Tue May 25 08:18:18 PDT 2021
Author: Anirudh Prasad
Date: 2021-05-25T11:18:12-04:00
New Revision: 993f38d0a7942d66d2dc1a64a1702bf9b15da87a
URL: https://github.com/llvm/llvm-project/commit/993f38d0a7942d66d2dc1a64a1702bf9b15da87a
DIFF: https://github.com/llvm/llvm-project/commit/993f38d0a7942d66d2dc1a64a1702bf9b15da87a.diff
LOG: [SystemZ][z/OS] Implement getHostCPUName for z/OS
- Currently, the host cpu information is not easily available on z/OS as in other platforms.
- This information is stored in the Communications Vector Table (https://www.ibm.com/docs/en/zos/2.2.0?topic=information-cvt-mapping)
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D102793
Added:
llvm/include/llvm/Support/BCD.h
Modified:
llvm/lib/Support/Host.cpp
llvm/unittests/Support/Host.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Support/BCD.h b/llvm/include/llvm/Support/BCD.h
new file mode 100644
index 000000000000..b09af6c1586b
--- /dev/null
+++ b/llvm/include/llvm/Support/BCD.h
@@ -0,0 +1,53 @@
+//===- llvm/Support/BCD.h - Binary-Coded Decimal utility functions -*- C++ -*-//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares some utility functions for encoding/decoding BCD values.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_BCD_H
+#define LLVM_SUPPORT_BCD_H
+
+#include <assert.h>
+#include <cstddef>
+#include <cstdint>
+
+namespace llvm {
+
+// Decode a packed BCD value.
+// Maximum value of int64_t is 9,223,372,036,854,775,807. These are 18 usable
+// decimal digits. Thus BCD numbers of up to 9 bytes can be converted.
+// Please note that s390 supports BCD numbers up to a length of 16 bytes.
+inline int64_t decodePackedBCD(const uint8_t *Ptr, size_t ByteLen,
+ bool IsSigned = true) {
+ assert(ByteLen >= 1 && ByteLen <= 9 && "Invalid BCD number");
+ int64_t Value = 0;
+ size_t RunLen = ByteLen - static_cast<unsigned>(IsSigned);
+ for (size_t I = 0; I < RunLen; ++I) {
+ uint8_t DecodedByteValue = ((Ptr[I] >> 4) & 0x0f) * 10 + (Ptr[I] & 0x0f);
+ Value = (Value * 100) + DecodedByteValue;
+ }
+ if (IsSigned) {
+ uint8_t DecodedByteValue = (Ptr[ByteLen - 1] >> 4) & 0x0f;
+ uint8_t Sign = Ptr[ByteLen - 1] & 0x0f;
+ Value = (Value * 10) + DecodedByteValue;
+ if (Sign == 0x0d || Sign == 0x0b)
+ Value *= -1;
+ }
+ return Value;
+}
+
+template <typename ResultT, typename ValT>
+inline ResultT decodePackedBCD(const ValT Val, bool IsSigned = true) {
+ return static_cast<ResultT>(decodePackedBCD(
+ reinterpret_cast<const uint8_t *>(&Val), sizeof(ValT), IsSigned));
+}
+
+} // namespace llvm
+
+#endif // LLVM_SUPPORT_BCD_H
diff --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp
index 6b6e907758bf..478351769705 100644
--- a/llvm/lib/Support/Host.cpp
+++ b/llvm/lib/Support/Host.cpp
@@ -18,6 +18,7 @@
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Config/llvm-config.h"
+#include "llvm/Support/BCD.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -296,6 +297,22 @@ StringRef sys::detail::getHostCPUNameForARM(StringRef ProcCpuinfoContent) {
return "generic";
}
+namespace {
+StringRef getCPUNameFromS390Model(unsigned int Id, bool HaveVectorSupport) {
+ if (Id >= 8561 && HaveVectorSupport)
+ return "z15";
+ if (Id >= 3906 && HaveVectorSupport)
+ return "z14";
+ if (Id >= 2964 && HaveVectorSupport)
+ return "z13";
+ if (Id >= 2827)
+ return "zEC12";
+ if (Id >= 2817)
+ return "z196";
+ return "generic";
+}
+} // end anonymous namespace
+
StringRef sys::detail::getHostCPUNameForS390x(StringRef ProcCpuinfoContent) {
// STIDP is a privileged operation, so use /proc/cpuinfo instead.
@@ -331,18 +348,8 @@ StringRef sys::detail::getHostCPUNameForS390x(StringRef ProcCpuinfoContent) {
if (Pos != StringRef::npos) {
Pos += sizeof("machine = ") - 1;
unsigned int Id;
- if (!Lines[I].drop_front(Pos).getAsInteger(10, Id)) {
- if (Id >= 8561 && HaveVectorSupport)
- return "z15";
- if (Id >= 3906 && HaveVectorSupport)
- return "z14";
- if (Id >= 2964 && HaveVectorSupport)
- return "z13";
- if (Id >= 2827)
- return "zEC12";
- if (Id >= 2817)
- return "z196";
- }
+ if (!Lines[I].drop_front(Pos).getAsInteger(10, Id))
+ return getCPUNameFromS390Model(Id, HaveVectorSupport);
}
break;
}
@@ -1229,6 +1236,29 @@ StringRef sys::getHostCPUName() {
StringRef Content = P ? P->getBuffer() : "";
return detail::getHostCPUNameForS390x(Content);
}
+#elif defined(__MVS__)
+StringRef sys::getHostCPUName() {
+ // Get pointer to Communications Vector Table (CVT).
+ // The pointer is located at offset 16 of the Prefixed Save Area (PSA).
+ // It is stored as 31 bit pointer and will be zero-extended to 64 bit.
+ int *StartToCVTOffset = reinterpret_cast<int *>(0x10);
+ // Since its stored as a 31-bit pointer, get the 4 bytes from the start
+ // of address.
+ int ReadValue = *StartToCVTOffset;
+ // Explicitly clear the high order bit.
+ ReadValue = (ReadValue & 0x7FFFFFFF);
+ char *CVT = reinterpret_cast<char *>(ReadValue);
+ // The model number is located in the CVT prefix at offset -6 and stored as
+ // signless packed decimal.
+ uint16_t Id = *(uint16_t *)&CVT[-6];
+ // Convert number to integer.
+ Id = decodePackedBCD<uint16_t>(Id, false);
+ // Check for vector support. It's stored in field CVTFLAG5 (offset 244),
+ // bit CVTVEF (X'80'). The facilities list is part of the PSA but the vector
+ // extension can only be used if bit CVTVEF is on.
+ bool HaveVectorSupport = CVT[244] & 0x80;
+ return getCPUNameFromS390Model(Id, HaveVectorSupport);
+}
#elif defined(__APPLE__) && defined(__aarch64__)
StringRef sys::getHostCPUName() {
return "cyclone";
diff --git a/llvm/unittests/Support/Host.cpp b/llvm/unittests/Support/Host.cpp
index 5911f8065fe6..fd025d670b4c 100644
--- a/llvm/unittests/Support/Host.cpp
+++ b/llvm/unittests/Support/Host.cpp
@@ -310,6 +310,54 @@ CPU revision : 0
EXPECT_EQ(sys::detail::getHostCPUNameForARM(Snapdragon865ProcCPUInfo), "cortex-a77");
}
+TEST(getLinuxHostCPUName, s390x) {
+ SmallVector<std::string> ModelIDs(
+ {"8561", "3906", "2964", "2827", "2817", "7"});
+ SmallVector<std::string> VectorSupport({"", "vx"});
+ SmallVector<StringRef> ExpectedCPUs;
+
+ // Model Id: 8561
+ ExpectedCPUs.push_back("zEC12");
+ ExpectedCPUs.push_back("z15");
+
+ // Model Id: 3906
+ ExpectedCPUs.push_back("zEC12");
+ ExpectedCPUs.push_back("z14");
+
+ // Model Id: 2964
+ ExpectedCPUs.push_back("zEC12");
+ ExpectedCPUs.push_back("z13");
+
+ // Model Id: 2827
+ ExpectedCPUs.push_back("zEC12");
+ ExpectedCPUs.push_back("zEC12");
+
+ // Model Id: 2817
+ ExpectedCPUs.push_back("z196");
+ ExpectedCPUs.push_back("z196");
+
+ // Model Id: 7
+ ExpectedCPUs.push_back("generic");
+ ExpectedCPUs.push_back("generic");
+
+ const std::string DummyBaseVectorInfo =
+ "features : esan3 zarch stfle msa ldisp eimm dfp edat etf3eh highgprs "
+ "te ";
+ const std::string DummyBaseMachineInfo =
+ "processor 0: version = FF, identification = 059C88, machine = ";
+
+ int CheckIndex = 0;
+ for (size_t I = 0; I < ModelIDs.size(); I++) {
+ for (size_t J = 0; J < VectorSupport.size(); J++) {
+ const std::string DummyCPUInfo = DummyBaseVectorInfo + VectorSupport[J] +
+ "\n" + DummyBaseMachineInfo +
+ ModelIDs[I];
+ EXPECT_EQ(sys::detail::getHostCPUNameForS390x(DummyCPUInfo),
+ ExpectedCPUs[CheckIndex++]);
+ }
+ }
+}
+
#if defined(__APPLE__) || defined(_AIX)
static bool runAndGetCommandOutput(
const char *ExePath, ArrayRef<llvm::StringRef> argv,
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