https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71976
Bug ID: 71976
Summary: [avr] insn-combiner deletes a live 64-bit shift
Product: gcc
Version: 6.1.1
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: gjl at gcc dot gnu.org
Target Milestone: ---
Target: avr
Created attachment 38953
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38953&action=edit
bug-combin.c: C test case
In the following test case, combine.c removes an 64-bit shift and generates
wrong code.
== Compile ==
$ avr-gcc -mmcu=atmega8 bug-combin.c -S -dp -Os -fdump-rtl-combine-details
-fdump-rtl-ud_dce
== configure ==
Target: avr
Configured with: ../../gcc.gnu.org/gcc-6-branch/configure --target=avr
--prefix=/local/gnu/install/gcc-6-avr-mingw32 --host=i386-mingw32
--build=x86_64-linux-gnu --enable-languages=c,c++ --disable-nls
--disable-shared --enable-lto --with-dwarf2 --with-gnu-ld --with-gnu-as
Thread model: single
gcc version 6.1.1 20160627 (GCC)
