commit	7203e00b5e4e83117524242df372c293b0952d60	[log] [tgz]
author	Dylan McKay <me@dylanmckay.io>	Fri Jan 18 06:10:41 2019 +0000
committer	Dylan McKay <me@dylanmckay.io>	Fri Jan 18 06:10:41 2019 +0000
tree	ca9dcb23c7032a23e6706cbbe0c4effb0c948b52
parent	f47bef661ec171a5de35816365c05738be7159cd [diff]

[AVR] Expand 8/16-bit multiplication to libcalls on MCUs that don't have hardware MUL

This change modifies the LLVM ISel lowering settings so that
8-bit/16-bit multiplication is expanded to calls into the compiler
runtime library if the MCU being targeted does not support
multiplication in hardware.

Before this, MUL instructions would be generated on CPUs like the
ATtiny85, triggering a CPU reset due to an illegal instruction at
runtime.

First raised in https://github.com/avr-rust/rust/issues/124.

llvm-svn: 351523

llvm/lib/Target/AVR/AVRISelLowering.cpp[diff]
llvm/lib/Target/AVR/AVRISelLowering.h[diff]
llvm/lib/Target/AVR/AVRSubtarget.cpp[diff]
llvm/lib/Target/AVR/AVRSubtarget.h[diff]
llvm/test/CodeGen/AVR/hardware-mul.ll[Renamed from llvm/test/CodeGen/AVR/mul.ll - diff]
llvm/test/CodeGen/AVR/smul-with-overflow.ll[diff]
llvm/test/CodeGen/AVR/software-mul.ll[Added - diff]
llvm/test/CodeGen/AVR/umul-with-overflow.ll[diff]

8 files changed

tree: ca9dcb23c7032a23e6706cbbe0c4effb0c948b52

README.md

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