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Move constant instructions into meta.

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Add new immediate types for floating point and vector immediates.
Use new immediates to define the constant value instructions in meta.

Split the fconst instruction into two: f32const and f64const. This prevents
confusion about the interpretation of 64 immediate bits when generating an f32
constant.

Add an immvector ImmediateType. This immediate type is variable length, and
provides all the bits of a SIMD vector directly.
This commit is contained in:
Jakob Stoklund Olesen
2016-03-31 14:18:02 -07:00
parent c3233fb332
commit e5305c249b
5 changed files with 87 additions and 30 deletions
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46
docs/langref.rst
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@@ -212,6 +212,23 @@ indicate the different kinds of immediate operands on an instruction.
signed two's complement integer. Instruction encodings may limit the valid
range.
.. type:: ieee32
A 32-bit immediate floating point number in the IEEE 754-2008 binary32
interchange format. All bit patterns are allowed.
.. type:: ieee64
A 64-bit immediate floating point number in the IEEE 754-2008 binary64
interchange format. All bit patterns are allowed.
.. type:: immvector
An immediate SIMD vector. This operand supplies all the bits of a SIMD
type, so it can have different sizes depending on the type produced. The
bits of the operand are interpreted as if the SIMD vector was loaded from
memory containing the immediate.
Control flow
============
@@ -628,31 +645,10 @@ A few instructions have variants that take immediate operands (e.g.,
:inst:`band` / :inst:`band_imm`), but in general an instruction is required to
load a constant into an SSA value.
.. inst:: a = iconst N
Integer constant.
Create a scalar integer SSA value with an immediate constant value, or an
integer vector where all the lanes have the same value.
:result Int a: Constant value.
.. inst:: a = fconst N
Floating point constant.
Create a :type:`f32` or :type:`f64` SSA value with an immediate constant
value, or a floating point vector where all the lanes have the same value.
:result Float a: Constant value.
.. inst:: a = vconst N
Vector constant (floating point or integer).
Create a SIMD vector value where the lanes don't have to be identical.
:result TxN a: Constant value.
.. autoinst:: iconst
.. autoinst:: f32const
.. autoinst:: f64const
.. autoinst:: vconst
.. inst:: a = select c, x, y