From 69042a5be4664c7928a21bd23e4f6795bfb19f60 Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Tue, 24 Jan 2017 12:26:54 -0800 Subject: [PATCH] i965/fs: Fix nir_op_fsign of absolute value. This does point at the front-end emitting silly code that could have been optimized out, but the current fsign implementation would emit bogus IR if abs was set for the argument (because it would apply the abs modifier on an unsigned integer type), and we shouldn't rely on the upper layer's optimization passes for correctness. Reviewed-by: Ian Romanick --- src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index e1ab59854e6..e0c2fa01ce3 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -701,7 +701,14 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr) break; case nir_op_fsign: { - if (type_sz(op[0].type) < 8) { + if (op[0].abs) { + /* Straightforward since the source can be assumed to be + * non-negative. + */ + set_condmod(BRW_CONDITIONAL_NZ, bld.MOV(result, op[0])); + set_predicate(BRW_PREDICATE_NORMAL, bld.MOV(result, brw_imm_f(1.0f))); + + } else if (type_sz(op[0].type) < 8) { /* AND(val, 0x80000000) gives the sign bit. * * Predicated OR ORs 1.0 (0x3f800000) with the sign bit if val is not -- 2.30.2