[PATCH] D138844: [PowerPC] Materialize floats in the range [-16.0, 15.0].

[Stefan Pintilie via Phabricator via llvm-commits]

stefanp added inline comments.


================
Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:17182
+      return true;
+    return Imm.isZero();
+  }
----------------
lei wrote:
> Previous behavour  is "fallthrough" which will result in a return of `Imm.isPosZero()`.  Do we not want the defalut to be same as before?
> Previous behavour  is "fallthrough" which will result in a return of `Imm.isPosZero()`.  Do we not want the defalut to be same as before?

Actually we can now handle negative zero as well for the types `f32` and `f64` due to this:
```
def : Pat<(f64 (fpimm0neg)),
          (f64 (XSNEGDP (XXLXORdpz)))>;

def : Pat<(f32 (fpimm0neg)),
          (f32 (COPY_TO_REGCLASS (XSNEGDP (XXLXORdpz)), VSSRC))>;
```
So, we can safely check for all zeros instead of just positive zero.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138844/new/

https://reviews.llvm.org/D138844