x86 Instruction Set Reference

CVTTSS2SI

Convert with Truncation Scalar Single-Precision Floating-Point Value to Doubleword Integer

Opcode	Mnemonic	Description
`F3 0F 2C /r`	`CVTTSS2SI r32, xmm/m32`	Convert one single-precision floating-point value from xmm/m32 to one signed doubleword integer in r32 using truncation.

Description
Converts a single-precision floating-point value in the source operand (second operand) to a signed doubleword integer in the destination operand (first operand). The source operand can be an XMM register or a 32-bit memory location. The destination operand is a general-purpose register. When the source operand is an XMM register, the single-precision floating-point value is contained in the low doubleword of the register. When a conversion is inexact, a truncated (round toward zero) result is returned. If a converted result is larger than the maximum signed doubleword integer, the floating-point invalid exception is raised, and if this exception is masked, the indefinite integer value (80000000H) is returned.

Description

Converts a single-precision floating-point value in the source operand (second operand) to a signed doubleword integer in the destination operand (first operand). The source operand can be an XMM register or a 32-bit memory location. The destination operand is a general-purpose register. When the source operand is an XMM register, the single-precision floating-point value is contained in the low doubleword of the register.

When a conversion is inexact, a truncated (round toward zero) result is returned. If a converted result is larger than the maximum signed doubleword integer, the floating-point invalid exception is raised, and if this exception is masked, the indefinite integer value (80000000H) is returned.

Operation
Destination[0..31] = ConvertFloatToIntegerTruncate(Source[0..31]);

SIMD Floating-Point Exceptions
Invalid, Precision.

Protected Mode Exceptions

`#GP(0)`	For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments.
`#GP(0)`	For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments.
`#SS(0)`	For an illegal address in the SS segment.
`#PF(fault-code)`	For a page fault.
`#NM`	If TS in CR0 is set.
`#XM`	If an unmasked SIMD floating-point exception and OSXMMEXCPT in CR4 is 1.
`#UD`	If an unmasked SIMD floating-point exception and OSXMMEXCPT in CR4 is 0. If EM in CR0 is set. If OSFXSR in CR4 is 0. If CPUID feature flag SSE is 0.

Real-Address Mode Exceptions

`#GP(0)`	If any part of the operand lies outside the effective address space from 0 to FFFFH.
`#GP(0)`	If any part of the operand lies outside the effective address space from 0 to FFFFH.
`#NM`	If TS in CR0 is set.
`#XM`	If an unmasked SIMD floating-point exception and OSXMMEXCPT in CR4 is 1.

Virtual-8086 Mode Exceptions

Same exceptions as in Real Address Mode

`#PF(fault-code)`	For a page fault.
`#PF(fault-code)`	For a page fault.

Instruction	Latency	Throughput	Execution Unit
`CPUID`	0F3n/0F2n/069n	0F3n/0F2n/069n	0F2n
`CVTTSS2SI r32, xmm`	9/8/4	2/2/1	FP_ADD FP_MISC