* instructions that require this support are derived from this
* class; the rest derive directly from AlphaStaticInst.
*/
- class AlphaFP : public AlphaStaticInst
+ class AlphaFP : public AlphaStaticInst
{
public:
/// Alpha FP rounding modes.
/// This instruction's trapping mode.
TrappingMode trappingMode;
+ /// Have we warned about this instruction's unsupported
+ /// rounding mode (if applicable)?
+ mutable bool warnedOnRounding;
+
+ /// Have we warned about this instruction's unsupported
+ /// trapping mode (if applicable)?
+ mutable bool warnedOnTrapping;
+
/// Constructor
AlphaFP(const char *mnem, MachInst _machInst, OpClass __opClass)
: AlphaStaticInst(mnem, _machInst, __opClass),
roundingMode((enum RoundingMode)FP_ROUNDMODE),
- trappingMode((enum TrappingMode)FP_TRAPMODE)
+ trappingMode((enum TrappingMode)FP_TRAPMODE),
+ warnedOnRounding(false),
+ warnedOnTrapping(false)
{
- if (trappingMode != Imprecise) {
- warn("precise FP traps unimplemented\n");
- }
}
int getC99RoundingMode(uint64_t fpcr_val) const;
}};
-def template FloatingPointDecode {{
- {
- bool fast = (FP_TRAPMODE == AlphaFP::Imprecise
- && FP_ROUNDMODE == AlphaFP::Normal);
- AlphaStaticInst *i =
- fast ? (AlphaStaticInst *)new %(class_name)sFast(machInst) :
- (AlphaStaticInst *)new %(class_name)sGeneral(machInst);
-
- if (FC == 31) {
- i = makeNop(i);
- }
-
- return i;
- }
-}};
-
output decoder {{
int
AlphaFP::getC99RoundingMode(uint64_t fpcr_val) const
{ "", "v", "INVTM2", "INVTM3", "INVTM4", "sv", "INVTM6", "svi" };
}};
+// FP instruction class execute method template. Handles non-standard
+// rounding modes.
+def template FloatingPointExecute {{
+ Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
+ Trace::InstRecord *traceData) const
+ {
+ if (trappingMode != Imprecise) {
+ warn("%s: non-standard trapping mode not supported",
+ generateDisassembly(0, NULL));
+ warnedOnTrapping = true;
+ }
+
+ Fault fault = No_Fault;
+
+ %(fp_enable_check)s;
+ %(op_decl)s;
+ %(op_rd)s;
+#if USE_FENV
+ if (roundingMode == Normal) {
+ %(code)s;
+ } else {
+ fesetround(getC99RoundingMode(xc->readFpcr()));
+ %(code)s;
+ fesetround(FE_TONEAREST);
+ }
+#else
+ if (roundingMode != Normal && !warnedOnRounding) {
+ warn("%s: non-standard rounding mode not supported",
+ generateDisassembly(0, NULL));
+ warnedOnRounding = true;
+ }
+ %(code)s;
+#endif
+
+ if (fault == No_Fault) {
+ %(op_wb)s;
+ }
+
+ return fault;
+ }
+}};
+
+// FP instruction class execute method template where no dynamic
+// rounding mode control is needed. Like BasicExecute, but includes
+// check & warning for non-standard trapping mode.
+def template FPFixedRoundingExecute {{
+ Fault %(class_name)s::execute(%(CPU_exec_context)s *xc,
+ Trace::InstRecord *traceData) const
+ {
+ if (trappingMode != Imprecise) {
+ warn("%s: non-standard trapping mode not supported",
+ generateDisassembly(0, NULL));
+ warnedOnTrapping = true;
+ }
+
+ Fault fault = No_Fault;
+
+ %(fp_enable_check)s;
+ %(op_decl)s;
+ %(op_rd)s;
+ %(code)s;
+
+ if (fault == No_Fault) {
+ %(op_wb)s;
+ }
+
+ return fault;
+ }
+}};
+
+def template FloatingPointDecode {{
+ {
+ AlphaStaticInst *i = new %(class_name)s(machInst);
+ if (FC == 31) {
+ i = makeNop(i);
+ }
+ return i;
+ }
+}};
+
// General format for floating-point operate instructions:
// - Checks trapping and rounding mode flags. Trapping modes
// currently unimplemented (will fail).
def format FloatingPointOperate(code, *opt_args) {{
iop = InstObjParams(name, Name, 'AlphaFP', CodeBlock(code), opt_args)
decode_block = FloatingPointDecode.subst(iop)
-
- fast_iop = InstObjParams(name, Name + 'Fast', 'AlphaFP',
- CodeBlock(code), opt_args)
- header_output = BasicDeclare.subst(fast_iop)
- decoder_output = BasicConstructor.subst(fast_iop)
- exec_output = BasicExecute.subst(fast_iop)
-
- gen_code_prefix = r'''
- fesetround(getC99RoundingMode(xc->readFpcr()));
-'''
-
- gen_code_suffix = r'''
- fesetround(FE_TONEAREST);
-'''
-
- gen_iop = InstObjParams(name, Name + 'General', 'AlphaFP',
- CodeBlock(gen_code_prefix + code + gen_code_suffix), opt_args)
- header_output += BasicDeclare.subst(gen_iop)
- decoder_output += BasicConstructor.subst(gen_iop)
- exec_output += BasicExecute.subst(gen_iop)
+ header_output = BasicDeclare.subst(iop)
+ decoder_output = BasicConstructor.subst(iop)
+ exec_output = FloatingPointExecute.subst(iop)
}};
+// Special format for cvttq where rounding mode is pre-decoded
+def format FPFixedRounding(code, class_suffix, *opt_args) {{
+ Name += class_suffix
+ iop = InstObjParams(name, Name, 'AlphaFP', CodeBlock(code), opt_args)
+ decode_block = FloatingPointDecode.subst(iop)
+ header_output = BasicDeclare.subst(iop)
+ decoder_output = BasicConstructor.subst(iop)
+ exec_output = FPFixedRoundingExecute.subst(iop)
+}};
////////////////////////////////////////////////////////////////////
//
0x1c: decode INTFUNC {
0x00: decode RA { 31: sextb({{ Rc.sb = Rb_or_imm< 7:0>; }}); }
0x01: decode RA { 31: sextw({{ Rc.sw = Rb_or_imm<15:0>; }}); }
- 0x32: ctlz({{
- uint64_t count = 0;
- uint64_t temp = Rb;
- if (temp<63:32>) temp >>= 32; else count += 32;
- if (temp<31:16>) temp >>= 16; else count += 16;
- if (temp<15:8>) temp >>= 8; else count += 8;
- if (temp<7:4>) temp >>= 4; else count += 4;
- if (temp<3:2>) temp >>= 2; else count += 2;
- if (temp<1:1>) temp >>= 1; else count += 1;
- if ((temp<0:0>) != 0x1) count += 1;
- Rc = count;
- }}, IntAluOp);
+ 0x32: ctlz({{
+ uint64_t count = 0;
+ uint64_t temp = Rb;
+ if (temp<63:32>) temp >>= 32; else count += 32;
+ if (temp<31:16>) temp >>= 16; else count += 16;
+ if (temp<15:8>) temp >>= 8; else count += 8;
+ if (temp<7:4>) temp >>= 4; else count += 4;
+ if (temp<3:2>) temp >>= 2; else count += 2;
+ if (temp<1:1>) temp >>= 1; else count += 1;
+ if ((temp<0:0>) != 0x1) count += 1;
+ Rc = count;
+ }}, IntAluOp);
- 0x33: cttz({{
- uint64_t count = 0;
- uint64_t temp = Rb;
- if (!(temp<31:0>)) { temp >>= 32; count += 32; }
- if (!(temp<15:0>)) { temp >>= 16; count += 16; }
- if (!(temp<7:0>)) { temp >>= 8; count += 8; }
- if (!(temp<3:0>)) { temp >>= 4; count += 4; }
- if (!(temp<1:0>)) { temp >>= 2; count += 2; }
- if (!(temp<0:0> & ULL(0x1))) count += 1;
- Rc = count;
- }}, IntAluOp);
+ 0x33: cttz({{
+ uint64_t count = 0;
+ uint64_t temp = Rb;
+ if (!(temp<31:0>)) { temp >>= 32; count += 32; }
+ if (!(temp<15:0>)) { temp >>= 16; count += 16; }
+ if (!(temp<7:0>)) { temp >>= 8; count += 8; }
+ if (!(temp<3:0>)) { temp >>= 4; count += 4; }
+ if (!(temp<1:0>)) { temp >>= 2; count += 2; }
+ if (!(temp<0:0> & ULL(0x1))) count += 1;
+ Rc = count;
+ }}, IntAluOp);
format FailUnimpl {
0x30: ctpop();
}
}
- // IEEE floating point
+ // Square root and integer-to-FP moves
0x14: decode FP_SHORTFUNC {
// Integer to FP register moves must have RB == 31
0x4: decode RB {
// IEEE floating point
0x16: decode FP_SHORTFUNC_TOP2 {
- // The top two bits of the short function code break this space
- // into four groups: binary ops, compares, reserved, and conversions.
- // See Table 4-12 of AHB.
+ // The top two bits of the short function code break this
+ // space into four groups: binary ops, compares, reserved, and
+ // conversions. See Table 4-12 of AHB. There are different
+ // special cases in these different groups, so we decode on
+ // these top two bits first just to select a decode strategy.
// Most of these instructions may have various trapping and
// rounding mode flags set; these are decoded in the
// FloatingPointDecode template used by the
// FloatingPointOperate format.
// add/sub/mul/div: just decode on the short function code
- // and source type.
- 0: decode FP_TYPEFUNC {
- format FloatingPointOperate {
+ // and source type. All valid trapping and rounding modes apply.
+ 0: decode FP_TRAPMODE {
+ // check for valid trapping modes here
+ 0,1,5,7: decode FP_TYPEFUNC {
+ format FloatingPointOperate {
#if SS_COMPATIBLE_FP
- 0x00: adds({{ Fc = Fa + Fb; }});
- 0x01: subs({{ Fc = Fa - Fb; }});
- 0x02: muls({{ Fc = Fa * Fb; }}, FloatMultOp);
- 0x03: divs({{ Fc = Fa / Fb; }}, FloatDivOp);
+ 0x00: adds({{ Fc = Fa + Fb; }});
+ 0x01: subs({{ Fc = Fa - Fb; }});
+ 0x02: muls({{ Fc = Fa * Fb; }}, FloatMultOp);
+ 0x03: divs({{ Fc = Fa / Fb; }}, FloatDivOp);
#else
- 0x00: adds({{ Fc.sf = Fa.sf + Fb.sf; }});
- 0x01: subs({{ Fc.sf = Fa.sf - Fb.sf; }});
- 0x02: muls({{ Fc.sf = Fa.sf * Fb.sf; }}, FloatMultOp);
- 0x03: divs({{ Fc.sf = Fa.sf / Fb.sf; }}, FloatDivOp);
+ 0x00: adds({{ Fc.sf = Fa.sf + Fb.sf; }});
+ 0x01: subs({{ Fc.sf = Fa.sf - Fb.sf; }});
+ 0x02: muls({{ Fc.sf = Fa.sf * Fb.sf; }}, FloatMultOp);
+ 0x03: divs({{ Fc.sf = Fa.sf / Fb.sf; }}, FloatDivOp);
#endif
- 0x20: addt({{ Fc = Fa + Fb; }});
- 0x21: subt({{ Fc = Fa - Fb; }});
- 0x22: mult({{ Fc = Fa * Fb; }}, FloatMultOp);
- 0x23: divt({{ Fc = Fa / Fb; }}, FloatDivOp);
- }
+ 0x20: addt({{ Fc = Fa + Fb; }});
+ 0x21: subt({{ Fc = Fa - Fb; }});
+ 0x22: mult({{ Fc = Fa * Fb; }}, FloatMultOp);
+ 0x23: divt({{ Fc = Fa / Fb; }}, FloatDivOp);
+ }
+ }
}
// Floating-point compare instructions must have the default
3: decode FA {
31: decode FP_TYPEFUNC {
format FloatingPointOperate {
- 0x2f: cvttq({{ Fc.sq = (int64_t)rint(Fb); }});
+ 0x2f: decode FP_ROUNDMODE {
+ format FPFixedRounding {
+ // "chopped" i.e. round toward zero
+ 0: cvttq({{ Fc.sq = (int64_t)trunc(Fb); }},
+ Chopped);
+ // round to minus infinity
+ 1: cvttq({{ Fc.sq = (int64_t)floor(Fb); }},
+ MinusInfinity);
+ }
+ default: cvttq({{ Fc.sq = (int64_t)nearbyint(Fb); }});
+ }
// The cvtts opcode is overloaded to be cvtst if the trap
// mode is 2 or 6 (which are not valid otherwise)
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