pto.pset_b32

pto.pset_b32 is part of the Predicate Generation And Algebra instruction set.

Summary

Construct a 32-bit predicate mask from a compile-time pattern token.

Mechanism

pto.pset_b32 sets the predicate register to a static pattern encoded by the pattern token. No runtime data is consumed; the entire result is determined at assembly time.

For a predicate register of width 32 bits:

\[ \mathrm{mask}_i = \begin{cases} 1 & \text{if lane } i \text{ matches pattern} \\ 0 & \text{otherwise} \end{cases} \]

The _b32 variant is the widest directly-constructable predicate segment. For wider predicates, use ppack to combine two _b32 predicates.

Syntax

PTO Assembly Form

%mask = pto.pset_b32 "PATTERN" : !pto.mask<b32>

AS Level 1 (SSA)

%mask = pto.pset_b32 "PATTERN" : !pto.mask<b32>

AS Level 2 (DPS)

pto.pset_b32 "PATTERN" outs(%mask : !pto.mask<b32>)

C++ Intrinsic

vector_bool mask = pset_b32(__cce_simd::PAT_VL16);

Inputs

Operand Type Description
"PATTERN" string attribute Compile-time pattern token

Supported Pattern Tokens

Pattern Predicate Width Meaning
PAT_ALL 32 All 32 bits set to 1
PAT_ALLF 32 All 32 bits set to 0
PAT_VL1 … PAT_VL32 32 First N bits set to 1
PAT_H 32 Bits 16–31 set to 1 (high half), bits 0–15 set to 0
PAT_Q 32 Bits 24–31 set to 1 (upper quarter), bits 0–23 set to 0
PAT_M3 32 Modular 3 pattern
PAT_M4 32 Modular 4 pattern

Expected Outputs

Result Type Description
%mask !pto.mask<b32> Constructed 32-bit predicate

Side Effects

None.

Constraints

Constraints

  • Pattern token validity: The pattern token MUST be valid for a 32-bit predicate width. Using a PAT_VL* token with N > 32 is illegal.
  • Predicate context: The _b32 predicate can be combined with another _b32 using ppack to form a 64-bit predicate for f32 vector width (N=64).

Exceptions

Exceptions

  • Illegal if the pattern token is not valid for the _b32 (32-bit) variant.
  • Illegal if the pattern token is not supported by the target profile.

Target-Profile Restrictions

Target-Profile Restrictions
Aspect CPU Sim A2/A3 A5
All pattern tokens Simulated Supported Supported
32-bit predicate width Supported Supported Supported

Examples

Construct all-active mask

#include <pto/pto-inst.hpp>
using namespace pto;

void set_all_active(RegBuf<predicate_t>& dst) {
    PSET_B32(dst, "PAT_ALL");
}

Use as active-lane mask for f32 vector operations

// All lanes active for f32 (64-bit predicate = pack two b32)
%all32 = pto.pset_b32 "PAT_ALL" : !pto.mask<b32>
%all64_lo = pto.pset_b32 "PAT_ALL" : !pto.mask<b32>
%all64_hi = pto.pset_b32 "PAT_ALL" : !pto.mask<b32>
%all64 = pto.ppack %all64_lo, "LOWER" : !pto.mask<b32> -> !pto.mask<b32>

Construct remainder mask

// First 12 lanes active (remainder loop)
%remainder = pto.pset_b32 "PAT_VL12" : !pto.mask<b32>