xscvqpsdz

VSX Scalar Convert with round to zero Quad-Precision to Signed Doubleword format X-form

xscvqpsdz VRT,VRB

Converts a quad-precision floating-point value to a signed doubleword integer, rounding towards zero.

Details

Converts a quad-precision floating-point value from the source VSR to a signed 64-bit doubleword integer using round-toward-zero mode and stores the result in the target VSR. Only the scalar element is processed. Invalid conversions saturate to the appropriate signed limit; FPSCR status is updated.

Pseudocode Operation

VRT[0:63] ← ConvertToSignedDoubleword_RoundTowardZero(VRB[0:127])
VRT[64:127] ← 0

Programming Note

The xscvqpsdz instruction is used to convert a quad-precision floating-point value to a signed doubleword integer, rounding towards zero. Ensure that the VSX facility is enabled (MSR.VSX=1) before using this instruction; otherwise, it will raise an exception. Be cautious of NaN and infinity values, as they result in specific outputs and set flags indicating exceptions. The instruction handles overflow by saturating to the maximum or minimum signed doubleword value.

Example

xscvqpsdz v1, v3

Encoding

Binary Layout
0
0
VRT
6
VRB
11
11000000000000000000000000000000
21
 
Format X-form
Opcode 0xFC190688
Extension VSX
Registers Altered FPSCR.FPRF, FPSCR.FR, FPSCR.FI, FPSCR.VXSNAN, FPSCR.VXCVI, FPSCR.XX

Operands

  • VRT
    Target Vector Register
  • VRB
    Source Vector Register