Xilinx Virtex-II Pro PPC405, User Manual

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March 2002 Release www.xilinx.com 691
Virtex-II Pro™ Platform FPGA Documentation 1-800-255-7778
Alphabetical Instruction Listing
R
mulhw
Multiply High Word
Description
The contents of register r A are multiplied with the contents of register r B, forming a 64-bit
signed product. The most-significant 32 bits of the result are loaded into register r D.
mulhwu should be used if the operands are to be interpreted as unsigned quantities.
This instruction can be used with mullw or mulli to calculate a full 64-bit product.
Pseudocode
prod
0:63
←
( r A)
×
( r B) signed
(
r D)
←
prod
0:31
Registers Altered
• r D.
• CR[CR0]
LT, GT, EQ, SO
if Rc
=
1.
Exceptions
Execution of any of the following invalid-instruction forms results in a boundedly-
undefined result rather than a program exception:
• Reserved bits containing a non-zero value.
Compatibility
This instruction is defined by the PowerPC user instruction-set architecture (UISA). It is
implemented by all PowerPC processors.
mulhw r D, r A, r B (Rc=0)
mulhw. r D, r A, r B (Rc=1)
XO Instruction Form
31 r D r A r B 0 75 Rc
0 6 1
1 1
6 2
1 2
2 3
1