Volume 3: Instruction Reference
3:77
fma
fma — Floating-point Multiply Add
Format:
(
qp
) fma.
pc
.
sf f
1
=
f
3
,
f
4
,
f
2
Description:
The product of FR
f
3
and FR
f
4
is computed to infinite precision and then FR
f
2
is added to
this product, again in infinite precision. The resulting value is then rounded to the
precision indicated by
pc
(and possibly FPSR.
sf
.
pc
and FPSR.
sf
.
wre
) using the rounding
mode specified by FPSR.
sf
.
rc
. The rounded result is placed in FR
f
1
.
If any of FR
f
3
, FR
f
4
, or FR
f
2
is a NaTVal, FR
f
1
is set to NaTVal instead of the computed
result.
If
f
2
is f0, an IEEE multiply operation is performed instead of a multiply and add.
“fmpy — Floating-point Multiply” on page 3:85.
The mnemonic values for the opcode’s
pc
are given in
. The
mnemonic values for
sf
are given in
. For the encodings and
interpretation of the status field’s
pc
,
wre
, and
rc
, refer to
and
.
Operation:
if (PR[
qp
]) {
fp_check_target_register(
f
1
);
if (tmp_isrcode = fp_reg_disabled(
f
1
,
f
2
,
f
3
,
f
4
))
disabled_fp_register_fault(tmp_isrcode, 0);
if (fp_is_natval(FR[
f
2
]) || fp_is_natval(FR[
f
3
]) ||
fp_is_natval(FR[
f
4
])) {
FR[
f
1
] = NATVAL;
fp_update_psr(
f
1
);
} else {
tmp_default_result = fma_exception_fault_check(
f
2
,
f
3
,
f
4
,
pc
,
sf,
&tmp_fp_env);
if (fp_raise_fault(tmp_fp_env))
fp_exception_fault(fp_decode_fault(tmp_fp_env));
if (fp_is_nan_or_inf(tmp_default_result)) {
FR[
f
1
] = tmp_default_result;
} else {
tmp_res = fp_mul(fp_reg_read(FR[
f
3
]), fp_reg_read(FR[
f
4
]));
if (
f
2
!= 0)
tmp_res = fp_add(tmp_res, fp_reg_read(FR[
f
2
]), tmp_fp_env);
FR[
f
1
] = fp_ieee_round(tmp_res, &tmp_fp_env);
}
fp_update_fpsr(
sf
, tmp_fp_env);
fp_update_psr(
f
1
);
if (fp_raise_traps(tmp_fp_env))
fp_exception_trap(fp_decode_trap(tmp_fp_env));
}
}
FP Exceptions:
Invalid Operation (V)
Underflow (U)
Denormal/Unnormal Operand (D)
Overflow (O)
Software Assist (SWA) fault
Inexact (I)
Software Assist (SWA) trap
Summary of Contents for ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Page 1: ......
Page 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Page 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Page 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Page 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
Page 230: ......
Page 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Page 380: ...2 132 Volume 2 Part 1 Interruptions ...
Page 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Page 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Page 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Page 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Page 808: ...2 560 Volume 2 Part 2 Context Management ...
Page 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Page 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Page 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Page 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
Page 891: ......
Page 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Page 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
Page 1296: ......
Page 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...