Revision: 5952
Author: [email protected]
Date: Wed Dec 8 10:08:23 2010
Log: Landing for Martyn Capewell.
Fix detection of VFP support on Nexus One.
BUG=none
TEST=none
Code review URL: http://codereview.chromium.org/5664004
http://code.google.com/p/v8/source/detail?r=5952
Modified:
/branches/bleeding_edge/src/platform-linux.cc
=======================================
--- /branches/bleeding_edge/src/platform-linux.cc Tue Dec 7 04:21:26 2010
+++ /branches/bleeding_edge/src/platform-linux.cc Wed Dec 8 10:08:23 2010
@@ -134,9 +134,7 @@
}
bool OS::ArmCpuHasFeature(CpuFeature feature) {
- const int max_items = 2;
- const char* search_strings[max_items] = { NULL, NULL };
- int search_items = 0;
+ const char* search_string = NULL;
// Simple detection of VFP at runtime for Linux.
// It is based on /proc/cpuinfo, which reveals hardware configuration
// to user-space applications. According to ARM (mid 2009), no similar
@@ -144,25 +142,26 @@
// so it's up to individual OSes to provide such.
switch (feature) {
case VFP3:
- search_strings[0] = "vfpv3";
- // Some old kernels will report vfp for A8, not vfpv3, so we check
for
- // A8 explicitely. The cpuinfo file report the CPU Part which for
Cortex
- // A8 is 0xc08.
- search_strings[1] = "0xc08";
- search_items = 2;
- ASSERT(search_items <= max_items);
+ search_string = "vfpv3";
break;
case ARMv7:
- search_strings[0] = "ARMv7" ;
- search_items = 1;
- ASSERT(search_items <= max_items);
+ search_string = "ARMv7";
break;
default:
UNREACHABLE();
}
- for (int i = 0; i < search_items; ++i) {
- if (CPUInfoContainsString(search_strings[i])) {
+ if (CPUInfoContainsString(search_string)) {
+ return true;
+ }
+
+ if (feature == VFP3) {
+ // Some old kernels will report vfp not vfpv3. Here we make a last
attempt
+ // to detect vfpv3 by checking for vfp *and* neon, since neon is only
+ // available on architectures with vfpv3.
+ // Checking neon on its own is not enough as it is possible to have
neon
+ // without vfp.
+ if (CPUInfoContainsString("vfp") && CPUInfoContainsString("neon")) {
return true;
}
}
--
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