Module: Mesa Branch: master Commit: 3f8e3c2bd8f54ae6817f7496be47f4e1a8860d9c URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=3f8e3c2bd8f54ae6817f7496be47f4e1a8860d9c
Author: Marek Olšák <[email protected]> Date: Sun Oct 22 15:54:23 2017 +0200 radeonsi: add a workaround for weird s_buffer_load_dword behavior on SI See my LLVM patch which fixes the root cause. Users have to apply this patch and then they have 2 choices: - Downgrade to LLVM 5.0 - Update to LLVM git after my LLVM patch is pushed. It won't be possible to use current and earlier development version of LLVM 6.0. Reviewed-by: Nicolai Hähnle <[email protected]> Cc: 17.3 <[email protected]> --- src/gallium/drivers/radeonsi/si_shader.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c index 4bf2a45eeb..4456026ac8 100644 --- a/src/gallium/drivers/radeonsi/si_shader.c +++ b/src/gallium/drivers/radeonsi/si_shader.c @@ -2013,14 +2013,21 @@ static LLVMValueRef fetch_constant( * code reducing SIMD wave occupancy from 8 to 2 in many cases. * * Using s_buffer_load_dword (x1) seems to be the best option right now. + * + * LLVM 5.0 on SI doesn't insert a required s_nop between SALU setting + * a descriptor and s_buffer_load_dword using it, so we can't expand + * the pointer into a full descriptor like below. We have to use + * s_load_dword instead. The only case when LLVM 5.0 would select + * s_buffer_load_dword (that we have to prevent) is when we use use + * a literal offset where we don't need bounds checking. */ -#if 0 /* keep this codepath disabled */ - if (!reg->Register.Indirect) { + if (ctx->screen->b.chip_class == SI && + HAVE_LLVM < 0x0600 && + !reg->Register.Indirect) { addr = LLVMBuildLShr(ctx->ac.builder, addr, LLVMConstInt(ctx->i32, 2, 0), ""); LLVMValueRef result = ac_build_load_invariant(&ctx->ac, ptr, addr); return bitcast(bld_base, type, result); } -#endif /* Do the bounds checking with a descriptor, because * doing computation and manual bounds checking of 64-bit _______________________________________________ mesa-commit mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-commit
