v_log_f32 GPU Native ISA AMD Vector
V LOG F32 Vector Arithmetic
v_log_f32
Calculate the base 2 logarithm of the single-precision float input and store the result into a vector register.
Encoding
Verified bit-level encoding data is not yet available for this instruction.
The instruction-format classification below (VOP1)
is well-documented and stable; exact per-target opcode/field bit positions have not
yet been imported from a verified source.
Operands
Operand details have not yet been curated for this instruction.
GFX Target Compatibility
| Target | Support |
|---|---|
| gfx1100 | ✅ Supported |
1ULP accuracy, denormals are flushed.
Related
More in Vector Arithmetic
Reference
AMDGPU / GFX ISA
Semantics
D0.f32 = log2(S0.f32)
Example
V_LOG_F32(0xff800000) => 0xffc00000 // log(-INF) = NAN
V_LOG_F32(0xbf800000) => 0xffc00000 // log(-1.0) = NAN
V_LOG_F32(0x80000000) => 0xff800000 // log(-0.0) = -INF
V_LOG_F32(0x00000000) => 0xff800000 // log(+0.0) = -INFReproduced from AMD's official "AMD Instinct MI300" ISA Reference Guide for technical accuracy.
Sources
- User Guide for AMDGPU Backend ↗ - LLVM Project
-
"AMD Instinct MI300" Instruction Set Architecture: Reference Guide ↗
- Advanced Micro Devices, Inc.
Reference Guide, page 195.