(gdb) bt
#0  0x00007fffefa5292a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa24bc380) at state_tracker/st_glsl_to_tgsi.cpp:1482
#1  0x00007fffefa5283a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa23b83b0) at state_tracker/st_glsl_to_tgsi.cpp:1456
#2  0x00007fffefa5283a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa2394bb0) at state_tracker/st_glsl_to_tgsi.cpp:1456
#3  0x00007fffefa5283a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa2394cb0) at state_tracker/st_glsl_to_tgsi.cpp:1456
#4  0x00007fffefa5283a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa222aa80) at state_tracker/st_glsl_to_tgsi.cpp:1456
#5  0x00007fffefa53950 in glsl_to_tgsi_visitor::try_emit_mad (mul_operand=1, ir=0x7fffa239e9f0, this=0x7fffa2229db0) at state_tracker/st_glsl_to_tgsi.cpp:1350
#6  glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa239e9f0) at state_tracker/st_glsl_to_tgsi.cpp:1436
#7  0x00007fffefa5283a in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa239eb60) at state_tracker/st_glsl_to_tgsi.cpp:1456
#8  0x00007fffefa53a7b in glsl_to_tgsi_visitor::try_emit_mad (mul_operand=1, ir=0x7fffa21f9360, this=0x7fffa2229db0) at state_tracker/st_glsl_to_tgsi.cpp:1354
#9  glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa21f9360) at state_tracker/st_glsl_to_tgsi.cpp:1436
#10 0x00007fffefa53a7b in glsl_to_tgsi_visitor::try_emit_mad (mul_operand=1, ir=0x7fffa23a1ff0, this=0x7fffa2229db0) at state_tracker/st_glsl_to_tgsi.cpp:1354
#11 glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa23a1ff0) at state_tracker/st_glsl_to_tgsi.cpp:1436
#12 0x00007fffefa67647 in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=0x7fffa21b7ac0) at state_tracker/st_glsl_to_tgsi.cpp:2778
#13 0x00007fffefa3e6a7 in glsl_to_tgsi_visitor::visit (this=0x7fffa2229db0, ir=<optimized out>) at state_tracker/st_glsl_to_tgsi.cpp:1334
#14 0x00007fffefb31ccd in visit_exec_list (list=<optimized out>, visitor=visitor@entry=0x7fffa2229db0) at ir.cpp:1879
#15 0x00007fffefa6a7a4 in get_mesa_program (ctx=ctx@entry=0x4923a40, shader_program=shader_program@entry=0x7fffa23b8530, shader=0x7fffa0688870) at state_tracker/st_glsl_to_tgsi.cpp:5535
#16 0x00007fffefa714c7 in st_link_shader (ctx=0x4923a40, prog=0x7fffa23b8530) at state_tracker/st_glsl_to_tgsi.cpp:5860
#17 0x00007fffefa8f12a in _mesa_glsl_link_shader (ctx=0x4923a40, prog=0x7fffa23b8530) at program/ir_to_mesa.cpp:2984
#18 0x00007fffef9636af in link_program (program=<optimized out>, ctx=0x4923a40) at main/shaderapi.c:1047
#19 _mesa_LinkProgram (programObj=<optimized out>) at main/shaderapi.c:1517
#20 0x000000000188ad9f in ?? ()
#21 0x0000000000ec1024 in ?? ()
#22 0x00000000010af130 in ?? ()
#23 0x00000000008993a4 in ?? ()
#24 0x000000000089a259 in ?? ()
#25 0x0000000000b8fa06 in ?? ()
#26 0x0000000000ba9062 in ?? ()
#27 0x0000000000c0cab7 in ?? ()
#28 0x0000000000db56f8 in ?? ()
#29 0x00007ffff7bc54a4 in start_thread () from /usr/lib/libpthread.so.0
#30 0x00007ffff646413d in clone () from /usr/lib/libc.so.6
(gdb)