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Is this a bug in GNU ld?
- To: egcs at egcs dot cygnus dot com
- Subject: Is this a bug in GNU ld?
- From: "John Phillips" <john_w_phillips at hotmail dot com>
- Date: Tue, 30 Nov 1999 17:56:34 PST
- Cc: john_w_phillips at hotmail dot com
I've run across a situation using a egcs MIPS-on-x86 cross compiler which
I think may be a GNU ld bug. GCC looks like it has 2 ways to generate
function calls in MIPS, using an address in the GOT (for general calls) or
by offsetting from the beginning of the current function (for local calls).
On my platform the latter doesn't get the correct address or offset to reach
When I look at the assembly code output from gcc (using objdump) the
function call is as follows:
48: 8f990000 lw $t9,0($gp)
4c: 00000000 nop
50: 273902b0 addiu $t9,$t9,688
54: 00000000 nop
58: 0320f809 jalr $t9
688 is the offset from the beginning of the caller to the beginning of the
callee (they're in the same file). Presumably, then, ld will change the lw
into $t9 to load the address of the caller. What actually gets generated,
cd28: 8f99801c lw $t9,-32740($gp)
cd2c: 00000000 nop
cd30: 2739cf90 addiu $t9,$t9,-12400
cd34: 00000000 nop
cd38: 0320f809 jalr $t9
The offset -32740 points to an uninitialized memory location, and -12400
would be the offset to the callee from the start of the text section if it
I'm running Redhat 6.0, gcc version egcs-2.90.29 980515 (egcs-1.0.3
release), and binutils version 2.8.1 (mips-linux), using BFD version 2.8.1.
Is there something I'm not doing correctly?
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