Shouldn't we also use abs for SQRT? For example, this adds abs for both RSQ and SQRT:
https://cgit.freedesktop.org/~mareko/mesa/commit/?id=5e0fb661a8e6ac5f7b2245dd31595155128e0664 Marek On Thu, Jan 5, 2017 at 5:47 PM, Samuel Pitoiset <samuel.pitoi...@gmail.com> wrote: > As explained by Nicolai, it seems like D3D always compute the > absolute value while GLSL says that the result of inversesqrt() > is undefined if x <= 0. Using the absolute value looks like safer > especially when the game has been ported from D3D to GL. > > This gets rid of the NaN values in the "Spec Ops: The Line" game > as well as the black squares. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97338 > > Signed-off-by: Samuel Pitoiset <samuel.pitoi...@gmail.com> > --- > > Nouveau also computes the absolute value before emitting RSQ. > > src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c > b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c > index 1966752cc0..ec6d6b0534 100644 > --- a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c > +++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c > @@ -754,9 +754,12 @@ static void emit_rsq(const struct lp_build_tgsi_action > *action, > struct lp_build_tgsi_context *bld_base, > struct lp_build_emit_data *emit_data) > { > - LLVMValueRef sqrt = > - lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_SQRT, > - emit_data->args[0]); > + LLVMValueRef abs, sqrt; > + > + abs = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_ABS, > + emit_data->args[0]); > + > + sqrt = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_SQRT, abs); > > emit_data->output[emit_data->chan] = > lp_build_emit_llvm_binary(bld_base, TGSI_OPCODE_DIV, > -- > 2.11.0 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
