Reviewers: Vyacheslav Egorov, Rodolph Perfetta,
Description:
ARM: Always enable ARMv7 when VFPv3 is enabled.
[email protected], [email protected]
BUG=v8:1317
TEST=
Please review this at http://codereview.chromium.org/6825037/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/arm/assembler-arm.cc
M src/flag-definitions.h
Index: src/arm/assembler-arm.cc
diff --git a/src/arm/assembler-arm.cc b/src/arm/assembler-arm.cc
index
73dddfd43eb53820f94f5f9381026dc84295ad7d..fd8e8b5d54ca444e3d81d23a62a0cc823c8394dd
100644
--- a/src/arm/assembler-arm.cc
+++ b/src/arm/assembler-arm.cc
@@ -59,12 +59,12 @@ static uint64_t CpuFeaturesImpliedByCompiler() {
#endif // def CAN_USE_ARMV7_INSTRUCTIONS
// If the compiler is allowed to use VFP then we can use VFP too in our
code
// generation even when generating snapshots. This won't work for cross
- // compilation.
+ // compilation. VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
#if defined(__VFP_FP__) && !defined(__SOFTFP__)
- answer |= 1u << VFP3;
+ answer |= 1u << VFP3 | 1u << ARMv7;
#endif // defined(__VFP_FP__) && !defined(__SOFTFP__)
#ifdef CAN_USE_VFP_INSTRUCTIONS
- answer |= 1u << VFP3;
+ answer |= 1u << VFP3 | 1u << ARMv7;
#endif // def CAN_USE_VFP_INSTRUCTIONS
return answer;
}
@@ -77,9 +77,10 @@ void CpuFeatures::Probe() {
initialized_ = true;
#endif
#ifndef __arm__
- // For the simulator=arm build, use VFP when FLAG_enable_vfp3 is enabled.
+ // For the simulator=arm build, use VFP when FLAG_enable_vfp3 is
+ // enabled. VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
if (FLAG_enable_vfp3) {
- supported_ |= 1u << VFP3;
+ supported_ |= 1u << VFP3 | 1u << ARMv7;
}
// For the simulator=arm build, use ARMv7 when FLAG_enable_armv7 is
enabled
if (FLAG_enable_armv7) {
@@ -93,10 +94,11 @@ void CpuFeatures::Probe() {
}
if (OS::ArmCpuHasFeature(VFP3)) {
- // This implementation also sets the VFP flags if
- // runtime detection of VFP returns true.
- supported_ |= 1u << VFP3;
- found_by_runtime_probing_ |= 1u << VFP3;
+ // This implementation also sets the VFP flags if runtime
+ // detection of VFP returns true. VFPv3 implies ARMv7, see ARM DDI
+ // 0406B, page A1-6.
+ supported_ |= 1u << VFP3 | 1u << ARMv7;
+ found_by_runtime_probing_ |= 1u << VFP3 | 1u << ARMv7;
}
if (OS::ArmCpuHasFeature(ARMv7)) {
Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index
d6cb6e372490aa1dfb20a83efcb35cf57c001a5b..15f8def0741d3d08190e7d5611e33e00a6f760db
100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -162,7 +162,8 @@ DEFINE_bool(enable_rdtsc, true,
DEFINE_bool(enable_sahf, true,
"enable use of SAHF instruction if available (X64 only)")
DEFINE_bool(enable_vfp3, true,
- "enable use of VFP3 instructions if available (ARM only)")
+ "enable use of VFP3 instructions if available - this implies "
+ "enabling ARMv7 instructions (ARM only)")
DEFINE_bool(enable_armv7, true,
"enable use of ARMv7 instructions if available (ARM only)")
DEFINE_bool(enable_fpu, true,
--
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