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authorNilay Vaish <nilay@cs.wisc.edu>2013-01-15 07:43:19 -0600
committerNilay Vaish <nilay@cs.wisc.edu>2013-01-15 07:43:19 -0600
commit91b00d98a5973d47b831495f5c668bbb185c7a15 (patch)
treed2108f83a8be89fdaeec5120c5f5ccb6744cdba1 /src/arch/x86
parent7fdcfdf08b9d654fcf311b213bd729cb957f822c (diff)
downloadgem5-91b00d98a5973d47b831495f5c668bbb185c7a15.tar.xz
x86: implement fabs, fchs instructions
Diffstat (limited to 'src/arch/x86')
-rw-r--r--src/arch/x86/isa/decoder/x87.isa4
-rw-r--r--src/arch/x86/isa/insts/x87/arithmetic/change_sign.py10
-rw-r--r--src/arch/x86/isa/microops/fpop.isa8
-rw-r--r--src/arch/x86/isa/operands.isa4
-rw-r--r--src/arch/x86/regs/misc.hh19
5 files changed, 41 insertions, 4 deletions
diff --git a/src/arch/x86/isa/decoder/x87.isa b/src/arch/x86/isa/decoder/x87.isa
index 3af68cd54..f278dc2f8 100644
--- a/src/arch/x86/isa/decoder/x87.isa
+++ b/src/arch/x86/isa/decoder/x87.isa
@@ -68,8 +68,8 @@ format WarnUnimpl {
}
0x4: decode MODRM_MOD {
0x3: decode MODRM_RM {
- 0x0: fchs();
- 0x1: fabs();
+ 0x0: Inst::FCHS();
+ 0x1: Inst::FABS();
0x4: ftst();
0x5: fxam();
default: Inst::UD2();
diff --git a/src/arch/x86/isa/insts/x87/arithmetic/change_sign.py b/src/arch/x86/isa/insts/x87/arithmetic/change_sign.py
index 059fb1ef1..779f1b5b2 100644
--- a/src/arch/x86/isa/insts/x87/arithmetic/change_sign.py
+++ b/src/arch/x86/isa/insts/x87/arithmetic/change_sign.py
@@ -36,6 +36,12 @@
# Authors: Gabe Black
microcode = '''
-# FABS
-# FCHS
+
+def macroop FABS {
+ absfp st(0), st(0)
+};
+
+def macroop FCHS {
+ chsfp st(0), st(0)
+};
'''
diff --git a/src/arch/x86/isa/microops/fpop.isa b/src/arch/x86/isa/microops/fpop.isa
index f6cbd2036..b9aceea09 100644
--- a/src/arch/x86/isa/microops/fpop.isa
+++ b/src/arch/x86/isa/microops/fpop.isa
@@ -331,4 +331,12 @@ let {{
else if(FpSrcReg1 == FpSrcReg2)
ccFlagBits = ccFlagBits | ZFBit;
'''
+
+ class absfp(FpUnaryOp):
+ code = 'FpDestReg = fabs(FpSrcReg1);'
+ flag_code = 'FSW &= (~CC1Bit);'
+
+ class chsfp(FpUnaryOp):
+ code = 'FpDestReg = (-1) * (FpSrcReg1);'
+ flag_code = 'FSW &= (~CC1Bit);'
}};
diff --git a/src/arch/x86/isa/operands.isa b/src/arch/x86/isa/operands.isa
index 05b127e37..bc6d1886c 100644
--- a/src/arch/x86/isa/operands.isa
+++ b/src/arch/x86/isa/operands.isa
@@ -158,7 +158,11 @@ def operands {{
# These register should needs to be more protected so that later
# instructions don't map their indexes with an old value.
'nccFlagBits': controlReg('MISCREG_RFLAGS', 65),
+
+ # Registers related to the state of x87 floating point unit.
'TOP': controlReg('MISCREG_X87_TOP', 66, ctype='ub'),
+ 'FSW': controlReg('MISCREG_FSW', 67, ctype='uw'),
+
# The segment base as used by memory instructions.
'SegBase': controlReg('MISCREG_SEG_EFF_BASE(segment)', 70),
diff --git a/src/arch/x86/regs/misc.hh b/src/arch/x86/regs/misc.hh
index 697c81fc9..5887e7486 100644
--- a/src/arch/x86/regs/misc.hh
+++ b/src/arch/x86/regs/misc.hh
@@ -79,6 +79,25 @@ namespace X86ISA
IDBit = 1 << 21
};
+ enum X87StatusBit {
+ // Exception Flags
+ IEBit = 1 << 0,
+ DEBit = 1 << 1,
+ ZEBit = 1 << 2,
+ OEBit = 1 << 3,
+ UEBit = 1 << 4,
+ PEBit = 1 << 5,
+
+ // !Exception Flags
+ StackFaultBit = 1 << 6,
+ ErrSummaryBit = 1 << 7,
+ CC0Bit = 1 << 8,
+ CC1Bit = 1 << 9,
+ CC2Bit = 1 << 10,
+ CC3Bit = 1 << 14,
+ BusyBit = 1 << 15,
+ };
+
enum MiscRegIndex
{
// Control registers