Command line:
gcc -fsched-pressure -fschedule-insns -c testcase.c
Tested revisions:
r156367 - fail
------- testcase.c --------
int foo(void)
{
return 0;
}
---------------------------
Output:
$ valgrind --track-origins=yes
/mnt/svn/gcc-trunk/binary-156367-lto/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/cc1plus
-fsched-pressure -fschedule-insns testcase.c
==15355== Memcheck, a memory error detector
==15355== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==15355== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
==15355== Command:
/mnt/svn/gcc-trunk/binary-156367-lto/libexec/gcc/x86_64-unknown-linux-gnu/4.5.0/cc1plus
-fsched-pressure -fschedule-insns testcase.c
==15355==
int foo()
Analyzing compilation unit
Performing interprocedural optimizations
<visibility> <*free_lang_data> <early_local_cleanups> <whole-program>
<inline>Assembling functions:
int foo()==15355== Conditional jump or move depends on uninitialised value(s)
==15355== at 0xD35F88: setup_insn_max_reg_pressure (haifa-sched.c:1597)
==15355== by 0x8A9C5F: schedule_insns (sched-rgn.c:2965)
==15355== by 0x8A9DFD: rest_of_handle_sched (sched-rgn.c:3512)
==15355== by 0x84FEEA: execute_one_pass (passes.c:1561)
==15355== by 0x850174: execute_pass_list (passes.c:1616)
==15355== by 0x850186: execute_pass_list (passes.c:1617)
==15355== by 0x945C34: tree_rest_of_compilation (tree-optimize.c:413)
==15355== by 0xAC70A0: cgraph_expand_function (cgraphunit.c:1543)
==15355== by 0xAC7E1F: cgraph_output_in_order (cgraphunit.c:1719)
==15355== by 0xAC9E4E: cgraph_optimize (cgraphunit.c:1867)
==15355== by 0xACA024: cgraph_finalize_compilation_unit (cgraphunit.c:1093)
==15355== by 0x54E4DA: cp_write_global_declarations (decl2.c:3798)
==15355== Uninitialised value was created by a heap allocation
==15355== at 0x4C280AC: malloc (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==15355== by 0xDE78D7: xmalloc (xmalloc.c:147)
==15355== by 0xD7CD78: sched_analyze_insn (sched-deps.c:2036)
==15355== by 0xD7D294: deps_analyze_insn (sched-deps.c:3248)
==15355== by 0xD7DA43: sched_analyze (sched-deps.c:3398)
==15355== by 0x8A819D: sched_rgn_compute_dependencies (sched-rgn.c:2726)
==15355== by 0x8A9827: schedule_insns (sched-rgn.c:2938)
==15355== by 0x8A9DFD: rest_of_handle_sched (sched-rgn.c:3512)
==15355== by 0x84FEEA: execute_one_pass (passes.c:1561)
==15355== by 0x850174: execute_pass_list (passes.c:1616)
==15355== by 0x850186: execute_pass_list (passes.c:1617)
==15355== by 0x945C34: tree_rest_of_compilation (tree-optimize.c:413)
==15355==
==15355== Conditional jump or move depends on uninitialised value(s)
==15355== at 0xD35F88: setup_insn_max_reg_pressure (haifa-sched.c:1597)
==15355== by 0xD3BE48: schedule_insn (haifa-sched.c:1632)
==15355== by 0xD3E9D0: schedule_block (haifa-sched.c:3143)
==15355== by 0x8A9B09: schedule_insns (sched-rgn.c:3001)
==15355== by 0x8A9DFD: rest_of_handle_sched (sched-rgn.c:3512)
==15355== by 0x84FEEA: execute_one_pass (passes.c:1561)
==15355== by 0x850174: execute_pass_list (passes.c:1616)
==15355== by 0x850186: execute_pass_list (passes.c:1617)
==15355== by 0x945C34: tree_rest_of_compilation (tree-optimize.c:413)
==15355== by 0xAC70A0: cgraph_expand_function (cgraphunit.c:1543)
==15355== by 0xAC7E1F: cgraph_output_in_order (cgraphunit.c:1719)
==15355== by 0xAC9E4E: cgraph_optimize (cgraphunit.c:1867)
==15355== Uninitialised value was created by a heap allocation
==15355== at 0x4C280AC: malloc (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==15355== by 0xDE78D7: xmalloc (xmalloc.c:147)
==15355== by 0xD7CD78: sched_analyze_insn (sched-deps.c:2036)
==15355== by 0xD7D294: deps_analyze_insn (sched-deps.c:3248)
==15355== by 0xD7DA43: sched_analyze (sched-deps.c:3398)
==15355== by 0x8A819D: sched_rgn_compute_dependencies (sched-rgn.c:2726)
==15355== by 0x8A9827: schedule_insns (sched-rgn.c:2938)
==15355== by 0x8A9DFD: rest_of_handle_sched (sched-rgn.c:3512)
==15355== by 0x84FEEA: execute_one_pass (passes.c:1561)
==15355== by 0x850174: execute_pass_list (passes.c:1616)
==15355== by 0x850186: execute_pass_list (passes.c:1617)
==15355== by 0x945C34: tree_rest_of_compilation (tree-optimize.c:413)
==15355==
With more complicated code more warnings are issued. I wasn't able to cause
difference in code generated with different --malloc-fill.
--
Summary: -fsched-pressure -fschedule-insns - valgrind warns about
using uninitialized variable
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: zsojka at seznam dot cz
GCC host triplet: x86(_64)-pc-linux-gnu
GCC target triplet: x86(_64)-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42941
