r275929 - in /branches/gcc-9-branch/gcc: Change...

[kito@gcc.gnu.org]

Author: kito
Date: Thu Sep 19 06:38:23 2019
New Revision: 275929

URL: https://gcc.gnu.org/viewcvs?rev=275929&root=gcc&view=rev
Log:
RISC-V: Fix bad insn splits with paradoxical subregs.

Shifting by more than the size of a SUBREG_REG doesn't work, so we either
need to disable splits if an input is paradoxical, or else we need to
generate a clean temporary for intermediate results.

Jakub wrote the first version of this patch, so gets primary credit for it.

	gcc/
	PR target/91635
	* config/riscv/riscv.md (zero_extendsidi2, zero_extendhi<GPR:mode>2,
	extend<SHORT:mode><SUPERQI:mode>2): Don't split if
	paradoxical_subreg_p (operands[0]).
	(*lshrsi3_zero_extend_3+1, *lshrsi3_zero_extend_3+2): Add clobber and
	use as intermediate value.

	gcc/testsuite/
	PR target/91635
	* gcc.c-torture/execute/pr91635.c: New test.
	* gcc.target/riscv/shift-shift-4.c: New test.
	* gcc.target/riscv/shift-shift-5.c: New test.

Added:
    branches/gcc-9-branch/gcc/testsuite/gcc.c-torture/execute/pr91635.c
    branches/gcc-9-branch/gcc/testsuite/gcc.target/riscv/shift-shift-4.c
    branches/gcc-9-branch/gcc/testsuite/gcc.target/riscv/shift-shift-5.c
Modified:
    branches/gcc-9-branch/gcc/ChangeLog
    branches/gcc-9-branch/gcc/config/riscv/riscv.md
    branches/gcc-9-branch/gcc/testsuite/ChangeLog