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cranelift: Remove booleans (#5031)

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Remove the boolean types from cranelift, and the associated instructions breduce, bextend, bconst, and bint. Standardize on using 1/0 for the return value from instructions that produce scalar boolean results, and -1/0 for boolean vector elements.

Fixes #3205

Co-authored-by: Afonso Bordado <afonso360@users.noreply.github.com>
Co-authored-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Co-authored-by: Chris Fallin <chris@cfallin.org>
This commit is contained in:
Trevor Elliott
2022-10-17 16:00:27 -07:00
committed by GitHub
parent 766ecb561e
commit 32a7593c94
242 changed files with 7695 additions and 10010 deletions
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cranelift/docs/ir.md
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@@ -138,25 +138,6 @@ All SSA values have a type which determines the size and shape (for SIMD
vectors) of the value. Many instructions are polymorphic -- they can operate on
different types.
### Boolean types
Boolean values are either true or false.
The `b1` type represents an abstract boolean value. It can only exist as
an SSA value, and can't be directly stored in memory. It can, however, be
converted into an integer with value 0 or 1 by the `bint` instruction (and
converted back with `icmp_imm` with 0).
Several larger boolean types are also defined, primarily to be used as SIMD
element types. They can be stored in memory, and are represented as either all
zero bits or all one bits.
- b1
- b8
- b16
- b32
- b64
### Integer types
Integer values have a fixed size and can be interpreted as either signed or
@@ -219,8 +200,8 @@ instructions either. The verifier enforces these rules.
### SIMD vector types
A SIMD vector type represents a vector of values from one of the scalar types
(boolean, integer, and floating point). Each scalar value in a SIMD type is
called a *lane*. The number of lanes must be a power of two in the range 2-256.
(integer, and floating point). Each scalar value in a SIMD type is called a
*lane*. The number of lanes must be a power of two in the range 2-256.
i%Bx%N
A SIMD vector of integers. The lane type `iB` is one of the integer
@@ -247,14 +228,6 @@ f64x%N
The size of a `f64` vector in memory is :math:`8N` bytes.
b1x%N
A boolean SIMD vector.
Boolean vectors are used when comparing SIMD vectors. For example,
comparing two `i32x4` values would produce a `b1x4` result.
Like the `b1` type, a boolean vector cannot be stored in memory.
### Pseudo-types and type classes
These are not concrete types, but convenient names used to refer to real types
@@ -314,12 +287,6 @@ ieee64
A 64-bit immediate floating point number in the IEEE 754-2008 binary64
interchange format. All bit patterns are allowed.
bool
A boolean immediate value, either false or true.
In the textual format, `bool` immediates appear as 'false'
and 'true'.
intcc
An integer condition code. See the `icmp` instruction for details.
@@ -790,10 +757,9 @@ an instruction is required to load a constant into an SSA value: `iconst`,
### Bitwise operations
The bitwise operations and operate on any value type: Integers, floating point
numbers, and booleans. When operating on integer or floating point types, the
bitwise operations are working on the binary representation of the values. When
operating on boolean values, the bitwise operations work as logical operators.
The bitwise operations and operate on any value type: Integers, and floating
point numbers. When operating on integer or floating point types, the bitwise
operations are working on the binary representation of the values.
The shift and rotate operations only work on integer types (scalar and vector).
The shift amount does not have to be the same type as the value being shifted.