From 765dd6534937e125b95c7998862b1a4ec76a22d8 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 25 Mar 2016 11:17:53 -0700 Subject: [PATCH] i965: Implement the new imod and irem opcodes Reviewed-by: Matt Turner --- src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 36 ++++++++++++++++++++++++++++++ src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 36 ++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index bd6314a..9b92968 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -853,9 +853,45 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr) unreachable("Should have been lowered by borrow_to_arith()."); case nir_op_umod: + case nir_op_irem: + /* According to the sign table for INT DIV in the Ivy Bridge PRM, it + * appears that our hardware just does the right thing for signed + * remainder. + */ bld.emit(SHADER_OPCODE_INT_REMAINDER, result, op[0], op[1]); break; + case nir_op_imod: { + /* Get a regular C-style remainder. If a % b == 0, set the predicate. */ + bld.emit(SHADER_OPCODE_INT_REMAINDER, result, op[0], op[1]); + + /* Math instructions don't support conditional mod */ + inst = bld.MOV(bld.null_reg_d(), result); + inst->conditional_mod = BRW_CONDITIONAL_NZ; + + /* Now, we need to determine if signs of the sources are different. + * When we XOR the sources, the top bit is 0 if they are the same and 1 + * if they are different. We can then use a conditional modifier to + * turn that into a predicate. This leads us to an XOR.l instruction. + * + * Technically, according to the PRM, you're not allowed to use .l on a + * XOR instruction. However, emperical experiments and Curro's reading + * of the simulator source both indicate that it's safe. + */ + fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_D); + inst = bld.XOR(tmp, op[0], op[1]); + inst->predicate = BRW_PREDICATE_NORMAL; + inst->conditional_mod = BRW_CONDITIONAL_L; + + /* If the result of the initial remainder operation is non-zero and the + * two sources have different signs, add in a copy of op[1] to get the + * final integer modulus value. + */ + inst = bld.ADD(result, result, op[1]); + inst->predicate = BRW_PREDICATE_NORMAL; + break; + } + case nir_op_flt: case nir_op_ilt: case nir_op_ult: diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp index e4e8c38..d24cdea 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp @@ -1116,9 +1116,45 @@ vec4_visitor::nir_emit_alu(nir_alu_instr *instr) break; case nir_op_umod: + case nir_op_irem: + /* According to the sign table for INT DIV in the Ivy Bridge PRM, it + * appears that our hardware just does the right thing for signed + * remainder. + */ emit_math(SHADER_OPCODE_INT_REMAINDER, dst, op[0], op[1]); break; + case nir_op_imod: { + /* Get a regular C-style remainder. If a % b == 0, set the predicate. */ + inst = emit_math(SHADER_OPCODE_INT_REMAINDER, dst, op[0], op[1]); + + /* Math instructions don't support conditional mod */ + inst = emit(MOV(dst_null_d(), src_reg(dst))); + inst->conditional_mod = BRW_CONDITIONAL_NZ; + + /* Now, we need to determine if signs of the sources are different. + * When we XOR the sources, the top bit is 0 if they are the same and 1 + * if they are different. We can then use a conditional modifier to + * turn that into a predicate. This leads us to an XOR.l instruction. + * + * Technically, according to the PRM, you're not allowed to use .l on a + * XOR instruction. However, emperical experiments and Curro's reading + * of the simulator source both indicate that it's safe. + */ + src_reg tmp = src_reg(this, glsl_type::ivec4_type); + inst = emit(XOR(dst_reg(tmp), op[0], op[1])); + inst->predicate = BRW_PREDICATE_NORMAL; + inst->conditional_mod = BRW_CONDITIONAL_L; + + /* If the result of the initial remainder operation is non-zero and the + * two sources have different signs, add in a copy of op[1] to get the + * final integer modulus value. + */ + inst = emit(ADD(dst, src_reg(dst), op[1])); + inst->predicate = BRW_PREDICATE_NORMAL; + break; + } + case nir_op_ldexp: unreachable("not reached: should be handled by ldexp_to_arith()"); -- 2.7.4