Example #1
0
    def test_inline_rsqrt(self):
        mod = Module.new(__name__)
        fnty = Type.function(Type.void(), [Type.pointer(Type.float())])
        fn = mod.add_function(fnty, "cu_rsqrt")
        bldr = Builder.new(fn.append_basic_block("entry"))

        rsqrt_approx_fnty = Type.function(Type.float(), [Type.float()])
        inlineasm = InlineAsm.get(rsqrt_approx_fnty, "rsqrt.approx.f32 $0, $1;", "=f,f", side_effect=True)
        val = bldr.load(fn.args[0])
        res = bldr.call(inlineasm, [val])

        bldr.store(res, fn.args[0])
        bldr.ret_void()

        # generate ptx
        nvvm.fix_data_layout(mod)
        nvvm.set_cuda_kernel(fn)
        nvvmir = str(mod)
        ptx = nvvm.llvm_to_ptx(nvvmir)
        self.assertTrue("rsqrt.approx.f32" in str(ptx))
Example #2
0
    def test_inline_rsqrt(self):
        mod = Module.new(__name__)
        fnty = Type.function(Type.void(), [Type.pointer(Type.float())])
        fn = mod.add_function(fnty, 'cu_rsqrt')
        bldr = Builder.new(fn.append_basic_block('entry'))

        rsqrt_approx_fnty = Type.function(Type.float(), [Type.float()])
        inlineasm = InlineAsm.get(rsqrt_approx_fnty,
                                  'rsqrt.approx.f32 $0, $1;',
                                  '=f,f', side_effect=True)
        val = bldr.load(fn.args[0])
        res = bldr.call(inlineasm, [val])

        bldr.store(res, fn.args[0])
        bldr.ret_void()

        # generate ptx
        nvvm.fix_data_layout(mod)
        nvvm.set_cuda_kernel(fn)
        nvvmir = str(mod)
        ptx = nvvm.llvm_to_ptx(nvvmir)
        self.assertTrue('rsqrt.approx.f32' in str(ptx))
Example #3
0
def _generic_array(context,
                   builder,
                   shape,
                   dtype,
                   symbol_name,
                   addrspace,
                   can_dynsized=False):
    elemcount = reduce(operator.mul, shape, 1)

    # Check for valid shape for this type of allocation.
    # Only 1d arrays can be dynamic.
    dynamic_smem = elemcount <= 0 and can_dynsized and len(shape) == 1
    if elemcount <= 0 and not dynamic_smem:
        raise ValueError("array length <= 0")

    # Check that we support the requested dtype
    other_supported_type = isinstance(dtype, (types.Record, types.Boolean))
    if dtype not in types.number_domain and not other_supported_type:
        raise TypeError("unsupported type: %s" % dtype)

    lldtype = context.get_data_type(dtype)
    laryty = Type.array(lldtype, elemcount)

    if addrspace == nvvm.ADDRSPACE_LOCAL:
        # Special case local address space allocation to use alloca
        # NVVM is smart enough to only use local memory if no register is
        # available
        dataptr = cgutils.alloca_once(builder, laryty, name=symbol_name)
    else:
        lmod = builder.module

        # Create global variable in the requested address space
        gvmem = lmod.add_global_variable(laryty, symbol_name, addrspace)
        # Specify alignment to avoid misalignment bug
        align = context.get_abi_sizeof(lldtype)
        # Alignment is required to be a power of 2 for shared memory. If it is
        # not a power of 2 (e.g. for a Record array) then round up accordingly.
        gvmem.align = 1 << (align - 1).bit_length()

        if dynamic_smem:
            gvmem.linkage = lc.LINKAGE_EXTERNAL
        else:
            ## Comment out the following line to workaround a NVVM bug
            ## which generates a invalid symbol name when the linkage
            ## is internal and in some situation.
            ## See _get_unique_smem_id()
            # gvmem.linkage = lc.LINKAGE_INTERNAL

            gvmem.initializer = lc.Constant.undef(laryty)

        # Convert to generic address-space
        conv = nvvmutils.insert_addrspace_conv(lmod, Type.int(8), addrspace)
        addrspaceptr = gvmem.bitcast(Type.pointer(Type.int(8), addrspace))
        dataptr = builder.call(conv, [addrspaceptr])

    targetdata = _get_target_data(context)
    lldtype = context.get_data_type(dtype)
    itemsize = lldtype.get_abi_size(targetdata)

    # Compute strides
    laststride = itemsize
    rstrides = []
    for i, lastsize in enumerate(reversed(shape)):
        rstrides.append(laststride)
        laststride *= lastsize
    strides = [s for s in reversed(rstrides)]
    kstrides = [context.get_constant(types.intp, s) for s in strides]

    # Compute shape
    if dynamic_smem:
        # Compute the shape based on the dynamic shared memory configuration.
        # Unfortunately NVVM does not provide an intrinsic for the
        # %dynamic_smem_size register, so we must read it using inline
        # assembly.
        get_dynshared_size = InlineAsm.get(Type.function(Type.int(), []),
                                           "mov.u32 $0, %dynamic_smem_size;",
                                           '=r',
                                           side_effect=True)
        dynsmem_size = builder.zext(builder.call(get_dynshared_size, []),
                                    Type.int(width=64))
        # Only 1-D dynamic shared memory is supported so the following is a
        # sufficient construction of the shape
        kitemsize = context.get_constant(types.intp, itemsize)
        kshape = [builder.udiv(dynsmem_size, kitemsize)]
    else:
        kshape = [context.get_constant(types.intp, s) for s in shape]

    # Create array object
    ndim = len(shape)
    aryty = types.Array(dtype=dtype, ndim=ndim, layout='C')
    ary = context.make_array(aryty)(context, builder)

    context.populate_array(ary,
                           data=builder.bitcast(dataptr, ary.data.type),
                           shape=kshape,
                           strides=kstrides,
                           itemsize=context.get_constant(types.intp, itemsize),
                           meminfo=None)
    return ary._getvalue()