r249046 - in /trunk/gcc: ChangeLog config/rs600...
segher@gcc.gnu.org
segher@gcc.gnu.org
Fri Jun 9 03:46:00 GMT 2017
Author: segher
Date: Fri Jun 9 03:46:08 2017
New Revision: 249046
URL: https://gcc.gnu.org/viewcvs?rev=249046&root=gcc&view=rev
Log:
rs6000: Don't add an immediate to r0 (PR80966)
If there is a large stack frame the rs6000 -fstack-limit code would
calculate the new stack pointer value using two insns (an addis and
an addi), with r0 as temporary. Such instructions do not exist.
This patch changes add<mode>3 to expand using a different strategy in
such cases; to FAIL if there is no way to do it (namely, if the source
is r0 and there is no way to get a temporary reg); and it changes
rs6000_emit_allocate_stack to assert gen_add3_insn did in fact emit
instructions.
PR target/80966
* config/rs6000/rs6000.c (rs6000_emit_allocate_stack): Assert that
gen_add3_insn did not fail.
* config/rs6000/rs6000.md (add<mode>3): If asked to add a constant to
r0, construct that number in a temporary reg and add that reg to r0.
If asked to put the result in r0 as well, fail.
gcc/testsuite/
* gcc.target/powerpc/stack-limit.c: New testcase.
Added:
trunk/gcc/testsuite/gcc.target/powerpc/stack-limit.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/rs6000/rs6000.c
trunk/gcc/config/rs6000/rs6000.md
trunk/gcc/testsuite/ChangeLog
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