When calculating whether a value can safely overflow for use by an
icmp, we weren't checking that the value couldn't wrap around. To do
this we need the icmp to be using a constant, as well as the incoming
add or sub.
bugzilla report: https://bugs.llvm.org/show_bug.cgi?id=39060
Differential Revision: https://reviews.llvm.org/D52463
llvm-svn: 343092
Originally committed in r339755 which was reverted in r339806 due to
an asan issue. The issue was caused by my assumption that operands to
a CallInst mapped to the FunctionType Params. CallInsts are now
handled by iterating over their ArgOperands instead of Operands.
Original Message:
Treat signed icmps as 'sinks', allowing them to be in the use-def
tree, enabling more promotions to be performed. As a sink, any
promoted incoming values need to be truncated before being used by
the signed icmp.
Differential Revision: https://reviews.llvm.org/D50067
llvm-svn: 339858
Treat signed icmps as 'sinks', allowing them to be in the use-def
tree, enabling more promotions to be performed. As a sink, any
promoted incoming values need to be truncated before being used by
the signed icmp.
Differential Revision: https://reviews.llvm.org/D50067
llvm-svn: 339755
Sam Parker