fcvt.s.d instruction not working with SSR

pulp-platform / snitch_cluster

An energy-efficient RISC-V floating-point compute cluster.

https://pulp-platform.github.io/snitch_cluster/

Apache License 2.0

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fcvt.s.d instruction not working with SSR #116

Closed gioelegott closed 3 months ago

gioelegott commented 8 months ago

Conversion from double to single precision (fcvt.s.d) isn't working when used in combination with ssr. It hangs indefinitely on verilator but works on banshee. This small test demonstrates the issue. test_fcvt.zip

and-ivanov commented 7 months ago

This seems to be more difficult to reproduce in the latest version (https://github.com/pulp-platform/snitch_cluster/commit/11d053489df24fd6057b5d985f6aa389cd507fed). Simulation is hanging only sometimes (may require multiple reruns) when built with multithreaded support

VLT_FLAGS='--threads 16' VLT_COBJ=work-vlt/vlt/verilated_threads.o VLT_CFLAGS=-DVL_THREADED \
    make -C target/snitch_cluster bin/snitch_cluster.vlt

colluca commented 3 months ago

This seems to be solved by https://github.com/pulp-platform/snitch_cluster/pull/158.