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/*========================== begin_copyright_notice ============================
Copyright (C) 2021 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ===========================*/
extern int __SubDeviceID;
int __attribute__((overloadable)) __spirv_BuiltInSubDeviceIDINTEL(void) {
if(BIF_FLAG_CTRL_GET(HasHWTileIDRegister)) {
return __builtin_IB_hw_tile_id();
}
// When __SubDeviceID is declared as an extern int,
// it is lowered to LLVM-IR like:
// @__SubDeviceID = external addrspace(1) global i32, align 4
// This global address is being then patched by the runtime
// and can be set to null when implicit scaling is disabled.
// One may wonder why __SubDeviceID is not declared as an extern int*
// In this case this would end up as a pointer to pointer in LLVM-IR.
// It would generate two loads and wouldn't be consistent with runtime behavior.
volatile int* p = &__SubDeviceID;
if (p == NULL) {
return 0;
}
return *p;
}
int __attribute__((overloadable)) __spirv_GlobalHWThreadIDINTEL(void) {
int subDeviceId = __spirv_BuiltInSubDeviceIDINTEL();
return __builtin_IB_hw_thread_id() + subDeviceId * BIF_FLAG_CTRL_GET(MaxHWThreadIDPerSubDevice);
}
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