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authorGabe Black <gblack@eecs.umich.edu>2010-06-02 12:58:06 -0500
committerGabe Black <gblack@eecs.umich.edu>2010-06-02 12:58:06 -0500
commit61b8e332253510c3c033153303b0a9ef09a31f1e (patch)
tree2759bddff5f2ed78f7cb18cf08c201e8ca1d378d /src/arch
parentc96f03a2507dd8445ee3abe2f81df919c4cc5e58 (diff)
downloadgem5-61b8e332253510c3c033153303b0a9ef09a31f1e.tar.xz
ARM: Implement the saturation instructions.
Diffstat (limited to 'src/arch')
-rw-r--r--src/arch/arm/insts/static_inst.hh39
-rw-r--r--src/arch/arm/isa/insts/misc.isa74
2 files changed, 109 insertions, 4 deletions
diff --git a/src/arch/arm/insts/static_inst.hh b/src/arch/arm/insts/static_inst.hh
index 3ff1d20cd..2c83ee79c 100644
--- a/src/arch/arm/insts/static_inst.hh
+++ b/src/arch/arm/insts/static_inst.hh
@@ -67,9 +67,9 @@ class ArmStaticInst : public StaticInst
int64_t midRes = sub ? (op1 - op2) : (op1 + op2);
if (bits(midRes, width) != bits(midRes, width - 1)) {
if (midRes > 0)
- res = (1LL << (width - 1)) - 1;
+ res = (LL(1) << (width - 1)) - 1;
else
- res = -(1LL << (width - 1));
+ res = -(LL(1) << (width - 1));
return true;
} else {
res = midRes;
@@ -77,13 +77,29 @@ class ArmStaticInst : public StaticInst
}
}
+ static bool
+ satInt(int32_t &res, int64_t op, int width)
+ {
+ width--;
+ if (op >= (LL(1) << width)) {
+ res = (LL(1) << width) - 1;
+ return true;
+ } else if (op < -(LL(1) << width)) {
+ res = -(LL(1) << width);
+ return true;
+ } else {
+ res = op;
+ return false;
+ }
+ }
+
template<int width>
static bool
uSaturateOp(uint32_t &res, int64_t op1, int64_t op2, bool sub=false)
{
int64_t midRes = sub ? (op1 - op2) : (op1 + op2);
- if (midRes >= (1 << width)) {
- res = (1 << width) - 1;
+ if (midRes >= (LL(1) << width)) {
+ res = (LL(1) << width) - 1;
return true;
} else if (midRes < 0) {
res = 0;
@@ -94,6 +110,21 @@ class ArmStaticInst : public StaticInst
}
}
+ static bool
+ uSatInt(int32_t &res, int64_t op, int width)
+ {
+ if (op >= (LL(1) << width)) {
+ res = (LL(1) << width) - 1;
+ return true;
+ } else if (op < 0) {
+ res = 0;
+ return true;
+ } else {
+ res = op;
+ return false;
+ }
+ }
+
// Constructor
ArmStaticInst(const char *mnem, ExtMachInst _machInst,
OpClass __opClass)
diff --git a/src/arch/arm/isa/insts/misc.isa b/src/arch/arm/isa/insts/misc.isa
index 3195bea65..db0bfac18 100644
--- a/src/arch/arm/isa/insts/misc.isa
+++ b/src/arch/arm/isa/insts/misc.isa
@@ -153,4 +153,78 @@ let {{
header_output += RevOpDeclare.subst(revshIop)
decoder_output += RevOpConstructor.subst(revshIop)
exec_output += PredOpExecute.subst(revshIop)
+
+ ssatCode = '''
+ int32_t operand = shift_rm_imm(Op1, shiftAmt, shiftType, 0);
+ int32_t res;
+ if (satInt(res, operand, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ else
+ CondCodes = CondCodes;
+ Dest = res;
+ '''
+ ssatIop = InstObjParams("ssat", "Ssat", "SatShiftOp",
+ { "code": ssatCode,
+ "predicate_test": predicateTest }, [])
+ header_output += SatShiftOpDeclare.subst(ssatIop)
+ decoder_output += SatShiftOpConstructor.subst(ssatIop)
+ exec_output += PredOpExecute.subst(ssatIop)
+
+ usatCode = '''
+ int32_t operand = shift_rm_imm(Op1, shiftAmt, shiftType, 0);
+ int32_t res;
+ if (uSatInt(res, operand, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ else
+ CondCodes = CondCodes;
+ Dest = res;
+ '''
+ usatIop = InstObjParams("usat", "Usat", "SatShiftOp",
+ { "code": usatCode,
+ "predicate_test": predicateTest }, [])
+ header_output += SatShiftOpDeclare.subst(usatIop)
+ decoder_output += SatShiftOpConstructor.subst(usatIop)
+ exec_output += PredOpExecute.subst(usatIop)
+
+ ssat16Code = '''
+ int32_t res;
+ uint32_t resTemp = 0;
+ CondCodes = CondCodes;
+ int32_t argLow = sext<16>(bits(Op1, 15, 0));
+ int32_t argHigh = sext<16>(bits(Op1, 31, 16));
+ if (satInt(res, argLow, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ replaceBits(resTemp, 15, 0, res);
+ if (satInt(res, argHigh, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ replaceBits(resTemp, 31, 16, res);
+ Dest = resTemp;
+ '''
+ ssat16Iop = InstObjParams("ssat16", "Ssat16", "SatOp",
+ { "code": ssat16Code,
+ "predicate_test": predicateTest }, [])
+ header_output += SatOpDeclare.subst(ssat16Iop)
+ decoder_output += SatOpConstructor.subst(ssat16Iop)
+ exec_output += PredOpExecute.subst(ssat16Iop)
+
+ usat16Code = '''
+ int32_t res;
+ uint32_t resTemp = 0;
+ CondCodes = CondCodes;
+ int32_t argLow = sext<16>(bits(Op1, 15, 0));
+ int32_t argHigh = sext<16>(bits(Op1, 31, 16));
+ if (uSatInt(res, argLow, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ replaceBits(resTemp, 15, 0, res);
+ if (uSatInt(res, argHigh, satImm))
+ CondCodes = CondCodes | (1 << 27);
+ replaceBits(resTemp, 31, 16, res);
+ Dest = resTemp;
+ '''
+ usat16Iop = InstObjParams("usat16", "Usat16", "SatOp",
+ { "code": usat16Code,
+ "predicate_test": predicateTest }, [])
+ header_output += SatOpDeclare.subst(usat16Iop)
+ decoder_output += SatOpConstructor.subst(usat16Iop)
+ exec_output += PredOpExecute.subst(usat16Iop)
}};