RISC-V problem with weak function references and -mcmodel=medany

[Sebastian Huber]

Changing the code to something like this

void f(void) __attribute__((__weak__));

void _start(void)
{
         void (*g)(void) = f;

         if (g != 0) {
                 (*g)();
         }
}

doesn't work either, since this is optimized to

         .option nopic
         .text
         .align  1
         .globl  _start
         .type   _start, @function
_start:
         lla     a5,f
         beqz    a5,.L1
         tail    f
.L1:
         ret
         .size   _start, .-_start
         .weak   f

Why doesn't the RISC-V generate a trampoline code to call far functions?

The non-optimized example code with "tail f" replaced by "jalr a5" links 
well:

         .option nopic
         .text
         .align  1
         .globl  _start
         .type   _start, @function
_start:
         addi    sp,sp,-32
         sd      ra,24(sp)
         sd      s0,16(sp)
         addi    s0,sp,32
         lla     a5,f
         sd      a5,-24(s0)
         ld      a5,-24(s0)
         beqz    a5,.L3
         ld      a5,-24(s0)
         jalr    a5
.L3:
         nop
         ld      ra,24(sp)
         ld      s0,16(sp)
         addi    sp,sp,32
         jr      ra
         .size   _start, .-_start
         .weak   f

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber@embedded-brains.de
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