[llvm-commits] [llvm] r159228 - /llvm/trunk/lib/Support/Host.cpp
Benjamin Kramer
benny.kra at googlemail.com
Tue Jun 26 14:36:32 PDT 2012
Author: d0k
Date: Tue Jun 26 16:36:32 2012
New Revision: 159228
URL: http://llvm.org/viewvc/llvm-project?rev=159228&view=rev
Log:
Implement getHostCPUName for ARM/linux. This will be used to implement -march=native in clang.
The cpuid registers are only available in privileged mode so we don't have
an OS-independent way of implementing this. ARM doesn't provide a list of
processor IDs so the list is somewhat incomplete.
Modified:
llvm/trunk/lib/Support/Host.cpp
Modified: llvm/trunk/lib/Support/Host.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Host.cpp?rev=159228&r1=159227&r2=159228&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Host.cpp (original)
+++ llvm/trunk/lib/Support/Host.cpp Tue Jun 26 16:36:32 2012
@@ -11,6 +11,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/DataStream.h"
@@ -450,6 +451,60 @@
.Case("POWER7", "pwr7")
.Default(generic);
}
+#elif defined(__linux__) && defined(__arm__)
+std::string sys::getHostCPUName() {
+ // The cpuid register on arm is not accessible from user space. On Linux,
+ // it is exposed through the /proc/cpuinfo file.
+ // Note: We cannot mmap /proc/cpuinfo here and then process the resulting
+ // memory buffer because the 'file' has 0 size (it can be read from only
+ // as a stream).
+
+ std::string Err;
+ DataStreamer *DS = getDataFileStreamer("/proc/cpuinfo", &Err);
+ if (!DS) {
+ DEBUG(dbgs() << "Unable to open /proc/cpuinfo: " << Err << "\n");
+ return "generic";
+ }
+
+ // Read 1024 bytes from /proc/cpuinfo, which should contain the CPU part line
+ // in all cases.
+ char buffer[1024];
+ size_t CPUInfoSize = DS->GetBytes((unsigned char*) buffer, sizeof(buffer));
+ delete DS;
+
+ StringRef Str(buffer, CPUInfoSize);
+
+ SmallVector<StringRef, 32> Lines;
+ Str.split(Lines, "\n");
+
+ // Look for the CPU implementer line.
+ StringRef Implementer;
+ for (unsigned I = 0, E = Lines.size(); I != E; ++I)
+ if (Lines[I].startswith("CPU implementer"))
+ Implementer = Lines[I].substr(15).ltrim("\t :");
+
+ if (Implementer == "0x41") // ARM Ltd.
+ // 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("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("0xc20", "cortex-m0")
+ .Case("0xc23", "cortex-m3")
+ .Case("0xc24", "cortex-m4")
+ .Default("generic");
+
+ return "generic";
+}
#else
std::string sys::getHostCPUName() {
return "generic";
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