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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-08-23 16:43:08 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-11-01 00:40:57 +0100 |
| commit | 226b62bc2ee4779447ce788d83aa0b409e384ec8 (patch) | |
| tree | ace913c378dd4085c34112c9e8602a7b39f75c27 /Documentation | |
| parent | 594c7389969f79919f1170693c970fb25b8bfe4d (diff) | |
| download | sparse-dev-226b62bc2ee4779447ce788d83aa0b409e384ec8.tar.gz | |
eval_insn: give an explicit type to compare's operands
The return type of IR instructions is stored in the field
::type of struct instruction and this struct has no space
to hold the type of the operand(s). This is not a problem
for most instructions because there is an easy way to get
the operands' type. For example, for binops both types
must be the same so they are used interchangeably.
However, for compare instructions both types can be different
and there is no easy way to get the type of the operands.
Currently, this is ignored and creates some errors. It
also blocks simplifications that need this type information.
But compares instructions need only 2 operands, there is
thus one 'slot' left. So, use this slot for the operands' type.
This solves the current errors, allows new simplifications
and has very little impact on existing code. Of course,
this type information needs now to be tracked and adjusted
whenever the operands change or an instruction is changed
into a compare.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/IR.rst | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/IR.rst b/Documentation/IR.rst index ff5af1c5..6330ee9c 100644 --- a/Documentation/IR.rst +++ b/Documentation/IR.rst @@ -134,6 +134,7 @@ They all have the following signature: * .src1, .src2: operands (types must be compatible) * .target: result of the operation (0/1 valued integer) * .type: type of .target, must be an integral type + * .itype: type of the input operands .. op:: OP_SET_EQ Compare equal. |