The specific description is [[ https://llvm.discourse.group/t/adding-unsigned-integer-ceil-and-floor-in-std-dialect/4541 | Adding unsigned integer ceil in Std Dialect ]] .
When we lower ceilDivOp this will generate below code, sometimes we know m and n are unsigned intergal.Here are some redundant judgments about positive and negative.
So we need to add some unsigned operations to simplify the instructions.
```
ceilDiv(n, m)
x = (m > 0) ? -1 : 1
return (n*m>0) ? ((n+x) / m) + 1 : - (-n / m)
```
unsigned operations:
```
ceilDivU(n, m)
return n ==0 ? 0 : ((n - 1) / m) + 1
```
Reviewed By: Mogball
Differential Revision: https://reviews.llvm.org/D113363
Precursor: https://reviews.llvm.org/D110200
Removed redundant ops from the standard dialect that were moved to the
`arith` or `math` dialects.
Renamed all instances of operations in the codebase and in tests.
Reviewed By: rriddle, jpienaar
Differential Revision: https://reviews.llvm.org/D110797
Create the Arithmetic dialect that contains basic integer and floating
point arithmetic operations. Ops that did not meet this criterion were
moved to the Math dialect.
First of two atomic patches to remove integer and floating point
operations from the standard dialect. Ops will be removed from the
standard dialect in a subsequent patch.
Reviewed By: ftynse, silvas
Differential Revision: https://reviews.llvm.org/D110200
