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authorJason Ekstrand <[email protected]>2016-03-25 11:13:40 -0700
committerJason Ekstrand <[email protected]>2016-04-13 15:44:00 -0700
commit745b3d295e0c432b95d43f979c74f9e91baaf6de (patch)
tree00f4c8721eb876bde18f860ebf64c493c59b40a6 /src
parentd880c6f9f59dac7cfe33713fff1c09c63ab7fb4f (diff)
nir: Add more modulus opcodes
These are all needed for SPIR-V Reviewed-by: Rob Clark <[email protected]> Reviewed-by: Matt Turner <[email protected]>
Diffstat (limited to 'src')
-rw-r--r--src/compiler/nir/nir_opcodes.py16
-rw-r--r--src/compiler/nir/nir_opt_algebraic.py1
2 files changed, 16 insertions, 1 deletions
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'),