From 745b3d295e0c432b95d43f979c74f9e91baaf6de Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 25 Mar 2016 11:13:40 -0700 Subject: [PATCH] nir: Add more modulus opcodes These are all needed for SPIR-V Reviewed-by: Rob Clark Reviewed-by: Matt Turner --- src/compiler/nir/nir_opcodes.py | 16 +++++++++++++++- src/compiler/nir/nir_opt_algebraic.py | 1 + 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/src/compiler/nir/nir_opcodes.py b/src/compiler/nir/nir_opcodes.py index 9f62e089e58..e75ca28cf0e 100644 --- a/src/compiler/nir/nir_opcodes.py +++ b/src/compiler/nir/nir_opcodes.py @@ -443,9 +443,23 @@ binop_convert("uadd_carry", tuint, tuint, commutative, "src0 + src1 < src0") binop_convert("usub_borrow", tuint, tuint, "", "src0 < src1") -binop("fmod", tfloat, "", "src0 - src1 * floorf(src0 / src1)") binop("umod", tuint, "", "src1 == 0 ? 0 : src0 % src1") +# For signed integers, there are several different possible definitions of +# "modulus" or "remainder". We follow the conventions used by LLVM and +# SPIR-V. The irem opcode implements the standard C/C++ signed "%" +# operation while the imod opcode implements the more mathematical +# "modulus" operation. For details on the difference, see +# +# http://mathforum.org/library/drmath/view/52343.html + +binop("irem", tint, "", "src1 == 0 ? 0 : src0 % src1") +binop("imod", tint, "", + "src1 == 0 ? 0 : ((src0 % src1 == 0 || (src0 >= 0) == (src1 >= 0)) ?" + " src0 % src1 : src0 % src1 + src1)") +binop("fmod", tfloat, "", "src0 - src1 * floorf(src0 / src1)") +binop("frem", tfloat, "", "src0 - src1 * truncf(src0 / src1)") + # # Comparisons # diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index ec8929a6d9f..2749b06aa69 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -287,6 +287,7 @@ optimizations = [ # Misc. lowering (('fmod', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'), + (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod'), (('uadd_carry', a, b), ('b2i', ('ult', ('iadd', a, b), a)), 'options->lower_uadd_carry'), (('usub_borrow', a, b), ('b2i', ('ult', a, b)), 'options->lower_usub_borrow'), -- 2.30.2