[libclc] libclc: frexp: fix implementation regarding denormals (PR #134823)

[Fraser Cormack via cfe-commits]

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@@ -26,7 +26,7 @@ __clc_frexp(__CLC_GENTYPE x, __CLC_ADDRESS_SPACE __CLC_INTN *ep) {
       (ai & (__CLC_INTN)MANTBITS_SP32);
 
   __CLC_INTN is_inf_nan_or_zero =
-      x == __CLC_FP_LIT(0.0) || __clc_isinf(x) || __clc_isnan(x);
+      ai == (__CLC_INTN)0 || __clc_isinf(x) || __clc_isnan(x);
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frasercrmck wrote:

I know this was in the original code that we're essentially reverting to, but do we know this is correct for `-0.0`?

https://github.com/llvm/llvm-project/pull/134823