Reviewers: Karl Klose,
Description:
ARM: Enhance the hardfloat support
The "simple" function with inline assembly for detecting hardfloat have been
changed to handle compiling without VFP and with thumb.
The SCons setting for the float abi now follows then naming used by the GCC
-mfloat-abi and soft has been added.
[email protected]
BUG=none
TEST=none
Please review this at http://codereview.chromium.org/6904126/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M SConstruct
M src/platform-linux.cc
Index: SConstruct
diff --git a/SConstruct b/SConstruct
index
e7a16ad1a6950d7eec6ad07646702f3175e956c1..bfba128d4d3e60bc8257763abbd0e8b860410edb
100644
--- a/SConstruct
+++ b/SConstruct
@@ -155,13 +155,19 @@ LIBRARY_FLAGS = {
'unalignedaccesses:off' : {
'CPPDEFINES' : ['CAN_USE_UNALIGNED_ACCESSES=0']
},
- 'armeabi:softfloat' : {
+ 'armeabi:soft' : {
+ 'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
+ 'simulator:none': {
+ 'CCFLAGS': ['-mfloat-abi=soft'],
+ }
+ },
+ 'armeabi:softfp' : {
'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=softfp'],
}
},
- 'armeabi:hardfloat' : {
+ 'armeabi:hard' : {
'CPPDEFINES' :
['USE_EABI_HARDFLOAT=1', 'CAN_USE_VFP_INSTRUCTIONS'],
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=hard'],
@@ -468,13 +474,19 @@ SAMPLE_FLAGS = {
},
'arch:arm': {
'LINKFLAGS': ARM_LINK_FLAGS,
- 'armeabi:softfloat' : {
+ 'armeabi:soft' : {
+ 'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
+ 'simulator:none': {
+ 'CCFLAGS': ['-mfloat-abi=soft'],
+ }
+ },
+ 'armeabi:softfp' : {
'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=softfp'],
}
},
- 'armeabi:hardfloat' : {
+ 'armeabi:hard' : {
'CPPDEFINES' :
['USE_EABI_HARDFLOAT=1', 'CAN_USE_VFP_INSTRUCTIONS'],
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=hard'],
@@ -591,12 +603,18 @@ PREPARSER_FLAGS = {
},
'arch:arm': {
'LINKFLAGS': ARM_LINK_FLAGS,
- 'armeabi:softfloat' : {
+ 'armeabi:soft' : {
+ 'CPPDEFINES' : ['USE_EABI_HARDFLOAT=0'],
+ 'simulator:none': {
+ 'CCFLAGS': ['-mfloat-abi=soft'],
+ }
+ },
+ 'armeabi:softfp' : {
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=softfp'],
}
},
- 'armeabi:hardfloat' : {
+ 'armeabi:hard' : {
'simulator:none': {
'CCFLAGS': ['-mfloat-abi=hard'],
}
@@ -962,8 +980,8 @@ SIMPLE_OPTIONS = {
'help': 'select profile guided optimization variant',
},
'armeabi': {
- 'values': ['hardfloat', 'softfloat'],
- 'default': 'softfloat',
+ 'values': ['hard', 'softfp', 'soft'],
+ 'default': 'softfp',
'help': 'generate calling conventiont according to selected ARM EABI
variant'
},
'mipsabi': {
Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index
d857cd90590dd74db84a6df1bebc2bffad42f930..b3b7fcb995876c08bdc01499518f5ee8d7ed4a14
100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -205,10 +205,32 @@ bool OS::ArmCpuHasFeature(CpuFeature feature) {
// calling this will return 1.0 and otherwise 0.0.
static void ArmUsingHardFloatHelper() {
asm("mov r0, #0");
- asm("mov r1, #0");
- asm("movt r1, #16368");
+#if defined(__VFP_FP__) && !defined(__SOFTFP__)
+ // Load 0x3ff00000 into r1 using instructions available in both ARM
+ // and Thumb mode.
+ asm("mov r1, #3");
+ asm("mov r2, #255");
+ asm("lsl r1, r1, #8");
+ asm("orr r1, r1, r2");
+ asm("lsl r1, r1, #16");
+ // For vmov d0, r0, r1 use ARM mode.
+#ifdef __thumb__
+ asm volatile(
+ "@ Enter ARM Mode \n\t"
+ " adr r3, 1f \n\t"
+ " bx r3 \n\t"
+ " .ALIGN 4 \n\t"
+ " .ARM \n"
+ "1: vmov d0, r0, r1 \n\t"
+ "@ Enter THUMB Mode\n\t"
+ " adr r3, 2f+1 \n\t"
+ " bx r3 \n\t"
+ " .THUMB \n"
+ "2: \n\t");
+#else
asm("vmov d0, r0, r1");
- asm("mov r0, #0");
+#endif // __thumb__
+#endif // defined(__VFP_FP__) && !defined(__SOFTFP__)
asm("mov r1, #0");
}
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