Horton

Fix jit compilation bug on wide tables.

Andres Freund <andres@anarazel.de>

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Commit: b238527664ec6f6c9d00dba4cc2f3dab1c8b8b04
Author: Andres Freund <andres@anarazel.de>
Date: 2018-11-27T18:07:03Z
Releases: 12.0 
Fix jit compilation bug on wide tables.

The function generated to perform JIT compiled tuple deforming failed
when HeapTupleHeader's t_hoff was bigger than a signed int8. I'd
failed to realize that LLVM's getelementptr would treat an int8 index
argument as signed, rather than unsigned.  That means that a hoff
larger than 127 would result in a negative offset being applied.  Fix
that by widening the index to 32bit.

Add a testcase with a wide table. Don't drop it, as it seems useful to
verify other tools deal properly with wide tables.

Thanks to Justin Pryzby for both reporting a bug and then reducing it
to a reproducible testcase!

Reported-By: Justin Pryzby
Author: Andres Freund
Discussion: https://postgr.es/m/20181115223959.GB10913@telsasoft.com
Backpatch: 11, just as jit compilation was

Files

PathChange+/−
src/backend/jit/llvm/llvmjit_deform.c modified +9 −3
src/test/regress/expected/create_table.out modified +10 −0
src/test/regress/expected/sanity_check.out modified +1 −0
src/test/regress/sql/create_table.sql modified +10 −0

Discussion