https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64003
Bug ID: 64003
Summary: valgrind complains about get_attr_length_nobnd in
insn-attrtab.c from i386.md
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: dmalcolm at gcc dot gnu.org
Host: x86_64-unknown-linux-gnu
Target: x86_64-unknown-linux-gnu
Build: x86_64-unknown-linux-gnu
Created attachment 34057
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34057&action=edit
Reproducer
When I run the jit testsuite under valgrind I consistently see reports from
here:
Conditional jump or move depends on uninitialised value(s)
at 0x5721AED: get_attr_length_nobnd(rtx_insn*) (i386.md:6236)
by 0x5715F3A: insn_min_length(rtx_insn*) (i386.md:510)
by 0x4F4BE0A: shorten_branches(rtx_insn*) (final.c:1208)
by 0x4F52A5A: rest_of_handle_shorten_branches() (final.c:4567)
by 0x4F52AAE: (anonymous
namespace)::pass_shorten_branches::execute(function*) (final.c:4596)
by 0x522354D: execute_one_pass(opt_pass*) (passes.c:2306)
by 0x52237C4: execute_pass_list_1(opt_pass*) (passes.c:2358)
by 0x52237F5: execute_pass_list_1(opt_pass*) (passes.c:2359)
by 0x52237F5: execute_pass_list_1(opt_pass*) (passes.c:2359)
by 0x5223832: execute_pass_list(function*, opt_pass*) (passes.c:2369)
by 0x4E4884F: cgraph_node::expand() (cgraphunit.c:1773)
by 0x4E48EE9: expand_all_functions() (cgraphunit.c:1909)
I can reproduce this with cc1 with the attached file at -O2 and above:
valgrind ./cc1 get-attr-length-i386.c -O2
This is with r217427 on x86_64-unknown-linux-gnu, configuring with:
--enable-valgrind-annotations
Turning off the writing of #line directives in read-md.c shows that it's at
line 18500 of the generated insn-attrtab.c:
==5819== at 0xD952E2: get_attr_length_nobnd(rtx_insn*)
(insn-attrtab.c:18500)
somewhere within this monster conditional:
18493 int
18494 get_attr_length_nobnd (rtx_insn *insn ATTRIBUTE_UNUSED)
18495 {
18496 switch (recog_memoized (insn))
18497 {
18498 case 610: /* *jcc_1 */
18499 extract_insn_cached (insn);
>18500 if ((((INSN_ADDRESSES_SET_P () ? INSN_ADDRESSES (INSN_UID
>(GET_CODE (operands[0]) == LABEL_REF ? XEXP (operands[0], 0) : operands[0])) :
>0) - (insn_current_reference_address (insn))) >= (-126)) &&
>(((INSN_ADDRESSES_SET_P () ? INSN_ADDRESSES (INSN_UID (GET_CODE (operands[0])
>== LABEL_REF ? XEXP (operands[0], 0) : operands[0])) : 0) -
>(insn_current_reference_address (insn))) < (128)))
