http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58169
Bug ID: 58169
Summary: missed load PRE related to array index truncation
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: amylaar at gcc dot gnu.org
Created attachment 30664
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30664&action=edit
test case for 32 bit targets
gcc.dg/tree-ssa/ssa-pre-21.c fails for avr (which has 16 bit int
and sizetype).
The computation of k + 1L is done as unsigned int (16 bit),
but later ++k is performed as unsigned long (32 bit), and thus
array[k+1] is not re-used.
The problem can also be seen on i686-pc-linux-gnu (32 bit) native
by changing the testcase to do the index computations in 64 bit, as
per attachment.
