Commit Graph

7 Commits (047be5c0c3b2f12c9321412518e17b7267fe14ea)

Author SHA1 Message Date
Paul Mackerras 0aa898c7a6 xics: Rework the irq_gen process
At present, the loop in the irq_gen process generates a chain of
comparators and other logic to work out the source number and priority
of the most-favoured (lowest priority number) pending interrupt.
This replaces that chain with (1) logic to generate an array of bits,
one per priority, indicating whether any interrupt is pending at that
priority, (2) a priority encoder to select the most favoured priority
with an interrupt pending, (3) logic to generate an array of bits, one
per source, indicating whether an interrupt is pending at the priority
calculated in step 2, and (4) a priority encoder to work out the
lowest numbered source that has an interrupt pending at the selected
priority.  This reduces LUT utilization.

The priority encoder function implemented here uses the optimized
count-leading-zeroes logic from helpers.vhdl.

Signed-off-by: Paul Mackerras <>
2 years ago
Paul Mackerras 1720a0584a Use alternative count-leading-zeroes algorithm in the FPU and LSU
Signed-off-by: Paul Mackerras <>
2 years ago
Paul Mackerras 9d285a265c core: Add support for single-precision FP loads and stores
This adds code to loadstore1 to convert between single-precision and
double-precision formats, and implements the lfs* and stfs*
instructions.  The conversion processes are described in Power ISA
v3.1 Book 1 sections 4.6.2 and 4.6.3.

These conversions take one cycle, so lfs* and stfs* are one cycle
slower than lfd* and stfd*.

Signed-off-by: Paul Mackerras <>
4 years ago
Paul Mackerras ec9b27660f execute: Copy XER[SO] to CR for cmp[i] and cmpl[i] instructions
We were copying in XER[SO] for the dot-form instructions but not the
explicit compare instructions.  Fix this.

Signed-off-by: Paul Mackerras <>
5 years ago
Anton Blanchard ae42370d24 Reformat helpers
Signed-off-by: Anton Blanchard <>
5 years ago
Michael Neuling 4d5abfb430 Remove dynamic ranges from code
Some VHDL compilers like verific [1] don't like these, so let's remove
them. Lots of random code changes, but passes make check.

Also add basic script to run verific and generate verilog.


Signed-off-by: Michael Neuling <>
5 years ago
Anton Blanchard 5a29cb4699 Initial import of microwatt
Signed-off-by: Anton Blanchard <>
5 years ago