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javacard:jcvm:7.5.67_iushr

7.5.67 iushr

Logical shift right int

Format

iushr

Forms

iushr = 82 (0x52)

Stack

…, value1.word1, value1.word2, value2.word1, value2.word2 → …, result.word1, result.word2

Description

Both value1 and value2 must be of type int. The values are popped from the operand stack. An int result is calculated by shifting the result right by s bit positions, with zero extension, where s is the value of the low five bits of value2. The result is pushed onto the operand stack.

Notes

If value1 is positive and s is value2& 0x1f, the result is the same as that of value1 » s; if value1 is negative, the result is equal to the value of the expression (value1 » s) + (2 « ~s). The addition of the (2 « ~s) term cancels out the propagated sign bit. The shift distance actually used is always in the range 0 to 31, inclusive, as if value2 were subjected to a bitwise logical AND with the mask value 0x1f.

If a virtual machine does not support the int data type, the iushr instruction will not be available.

javacard/jcvm/7.5.67_iushr.txt · Last modified: 2017/05/13 04:09 (external edit)