Bug 113

Summary: FCVT unit tests have too great a dynamic range
Product: Libre-SOC's first SoC Reporter: Luke Kenneth Casson Leighton <lkcl>
Component: ALU (including IEEE754 16/32/64-bit FPU)Assignee: Luke Kenneth Casson Leighton <lkcl>
Status: RESOLVED FIXED    
Severity: enhancement CC: libre-soc-bugs
Priority: ---    
Version: unspecified   
Hardware: PC   
OS: Linux   
NLnet milestone: NLnet.2019.02.012 total budget (EUR) for completion of task and all subtasks: 250
budget (EUR) for this task, excluding subtasks' budget: 250 parent task for budget allocation: 48
child tasks for budget allocation: The table of payments (in EUR) for this task; TOML format:
lkcl={amount=250, paid=2020-03-12}
Bug Depends on:    
Bug Blocks: 48    

Description Luke Kenneth Casson Leighton 2019-07-21 10:31:20 BST 
the range on the higher-sized to lower-sized randomised unit tests
give input values that are so large, they're almost exclusively
converted to +INF (or hit the -ve limit - 0 for unsigned, -INF for signed)

better tests are needed.
Comment 1 Luke Kenneth Casson Leighton 2019-08-01 01:00:34 BST 
this for:

* fcvt float2int (large FP to smaller int)
* int2float (for FP16/32/64 to FP16)
* fcvt FP to FP (large FP to smaller FP)

int input is fairly easy to deal with: test within "close" range.
FP however needs *FP* numbers to be generated that will (or will
almost) fit into the target int range.
Comment 2 Luke Kenneth Casson Leighton 2020-02-10 15:10:56 GMT 
https://git.libre-riscv.org/?p=ieee754fpu.git;a=commitdiff;h=6ea789c9e5a54e7dfbfbd96cb0c620e52b01c2a4

added appx-range within chosen int (-INTMAX*2 to +INTMAX*2) now need one
that is very close to the limits.
Comment 3 Luke Kenneth Casson Leighton 2020-02-11 22:40:39 GMT 
also added floating-point conversion tests which convert numbers just at
the limits of accuracy (or INF) of the target number.