On 21/08/18 22:41, Luc Van Oostenryck wrote:
> In simplify_mask_or(), two calls to simplify_mask_or_and() are
> made: one for each operand of the OR instruction.
> These two calls are guarded by a test checking the presence of
> the AND instruction. If it is the case for the first operand,
> the second operand is never considered for simplification,
> even if no simplications has been made.
s/simplications/simplifications/
>
> Fix this by testing the return value of simplify_and_or_mask()
> and let's do the second call if no simplifications could be
> done in the first one.
>
> For example, code like:
> int foo(int x, int y, int a)
> {
> return ((a & 0xf000) | (x & y)) & 0x0fff;
> }
>
> was expectedly simplified into:
> foo:
> and.32 %r5 <- %arg1, %arg2
> and.32 %r7 <- %r5, $0xfff
> ret.32 %r7
>
> while the same code with the operands of the OR swaped was not:
s/swaped/swapped/
ATB,
Ramsay Jones
> int foo(int x, int y, int a)
> {
> return ((x & y) | (a & 0xf000)) & 0x0fff;
> }
>
> resulted in the non-optimized:
> foo:
> and.32 %r3 <- %arg1, %arg2
> and.32 %r5 <- %arg3, $0xf000
> or.32 %r6 <- %r3, %r5
> and.32 %r7 <- %r6, $0xfff
> ret.32 %r7
>
> but now the simplification can also be done:
> foo:
> and.32 %r3 <- %arg1, %arg2
> and.32 %r7 <- %r3, $0xfff
> ret.32 %r7
>
> Note: it would be simpler to unconditionally do both calls
> but this is unsafe because some of the concerned
> instructions, needed in the second call, could have
> been simplified away in the first one.
>
> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
> ---
> simplify.c | 7 +++++--
> validation/optim/and-or-bfx.c | 1 -
> validation/optim/and-or-lsrx.c | 1 -
> validation/optim/and-or-maskx.c | 1 -
> 4 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/simplify.c b/simplify.c
> index 969fd15bb..2431a90cb 100644
> --- a/simplify.c
> +++ b/simplify.c
> @@ -589,11 +589,14 @@ static int simplify_mask_or(struct instruction *insn, unsigned long long mask, s
> {
> pseudo_t src1 = or->src1;
> pseudo_t src2 = or->src2;
> + int rc;
>
> if (def_opcode(src1) == OP_AND)
> - return simplify_mask_or_and(insn, mask, src1, src2);
> + if ((rc = simplify_mask_or_and(insn, mask, src1, src2)))
> + return rc;
> if (def_opcode(src2) == OP_AND)
> - return simplify_mask_or_and(insn, mask, src2, src1);
> + if ((rc = simplify_mask_or_and(insn, mask, src2, src1)))
> + return rc;
> return 0;
> }
>
> diff --git a/validation/optim/and-or-bfx.c b/validation/optim/and-or-bfx.c
> index ed04e2d31..57a54cf5e 100644
> --- a/validation/optim/and-or-bfx.c
> +++ b/validation/optim/and-or-bfx.c
> @@ -11,7 +11,6 @@ void foo(struct s *p, int a, int b)
> /*
> * check-name: and-or-bfx
> * check-command: test-linearize -Wno-decl $file
> - * check-known-to-fail
> *
> * check-output-ignore
> * check-output-pattern(2): and\\.
> diff --git a/validation/optim/and-or-lsrx.c b/validation/optim/and-or-lsrx.c
> index 0b7d8f445..31adca92e 100644
> --- a/validation/optim/and-or-lsrx.c
> +++ b/validation/optim/and-or-lsrx.c
> @@ -6,7 +6,6 @@ unsigned int foo(unsigned int x, unsigned int y, unsigned int a)
> /*
> * check-name: and-or-lsrx
> * check-command: test-linearize -Wno-decl $file
> - * check-known-to-fail
> *
> * check-output-ignore
> * check-output-pattern(1): and\\.
> diff --git a/validation/optim/and-or-maskx.c b/validation/optim/and-or-maskx.c
> index 497c1a60e..21d44e8d0 100644
> --- a/validation/optim/and-or-maskx.c
> +++ b/validation/optim/and-or-maskx.c
> @@ -6,7 +6,6 @@ int foo(int x, int y, int a)
> /*
> * check-name: and-or-maskx
> * check-command: test-linearize -Wno-decl $file
> - * check-known-to-fail
> *
> * check-output-ignore
> * check-output-pattern(2): and\\.
>
