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James Hogan authored
uasm_in_compat_space_p() determines whether the given value is in the 32-bit compatibility part of the 64-bit address space, i.e. is in 32-bit sign-extended form, however it only handles the top half of the value space (corresponding to the kernel compatibility segments in the upper half of the address space). Since values < 2^31 (corresponding to the low 2GiB of the address space) can also be handled using 32-bit instructions (e.g. a LUI and ADDIU) rather than convoluted 64-bit immediate generation, rewrite it with a cast to check whether the address matches its 32-bit sign extended form. This allows UASM_i_LA to be used to generate arbitrary 32-bit immediates more efficiently on 64-bit CPUs, i.e. more like the li (load immediate) pseudo-instruction. For example this code to load the immediate (ST0_EXL | KSU_USER | ST0_BEV | ST0_KX) into k0 with UASM_i_LA(): lui k0,0x0 dsll k0,k0,0x10 daddiu k0,k0,64 dsll k0,k0,0x10 daddiu k0,k0,146 Changes to this more efficient version: lui k0,0x40 addiu k0,k0,146 Signed-off-by:
James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13778/Signed-off-by:
Ralf Baechle <ralf@linux-mips.org>
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