[v2] bpf: add inline memmove and memcpy expansion
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Commit Message
[Changes from v1: Jose's review comments, all of which I agree with.
- Fix 'implments' typo in commit message.
- Change check that alignment is CONST_INT to gcc_assert ().
- Change default case in alignment switch to gcc_unreachable ().
- Reword error message for non-constant size memmove/memcpy, and
update test for the error accordingly.
- Delete CPYMEM_EXPAND_ERR macro, since it was now only used in
one place. ]
BPF programs are not typically linked, which means we cannot fall back
on library calls to implement __builtin_{memmove,memcpy} and should
always expand them inline if possible.
GCC already successfully expands these builtins inline in many cases,
but failed to do so for a few for simple cases involving overlapping
memmove in the kernel BPF selftests and was instead emitting a libcall.
This patch implements a simple inline expansion of memcpy and memmove in
the BPF backend in a verifier-friendly way, with the caveat that the
size must be an integer constant, which is also required by clang.
Tested for bpf-unknown-none on x86_64-linux-gnu host.
Also tested against the BPF verifier by compiling and loading a test
program with overlapping memmove (essentially the memmove-1.c test)
which failed before due to a libcall, and now successfully loads and
passes the verifier.
gcc/
* config/bpf/bpf-protos.h (bpf_expand_cpymem): New.
* config/bpf/bpf.cc: (emit_move_loop, bpf_expand_cpymem): New.
* config/bpf/bpf.md: (cpymemdi, movmemdi): New define_expands.
gcc/testsuite/
* gcc.target/bpf/memcpy-1.c: New test.
* gcc.target/bpf/memmove-1.c: New test.
* gcc.target/bpf/memmove-2.c: New test.
---
gcc/config/bpf/bpf-protos.h | 2 +
gcc/config/bpf/bpf.cc | 116 +++++++++++++++++++++++
gcc/config/bpf/bpf.md | 36 +++++++
gcc/testsuite/gcc.target/bpf/memcpy-1.c | 26 +++++
gcc/testsuite/gcc.target/bpf/memmove-1.c | 46 +++++++++
gcc/testsuite/gcc.target/bpf/memmove-2.c | 23 +++++
6 files changed, 249 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/bpf/memcpy-1.c
create mode 100644 gcc/testsuite/gcc.target/bpf/memmove-1.c
create mode 100644 gcc/testsuite/gcc.target/bpf/memmove-2.c
Comments
Hi Faust.
> +bool
> +bpf_expand_cpymem (rtx *operands, bool is_move)
> +{
> + /* Size must be constant for this expansion to work. */
> + if (!CONST_INT_P (operands[2]))
> + {
> + const char *name = is_move ? "memmove" : "memcpy";
> + if (flag_building_libgcc)
> + warning (RTL_LOCATION (operands[2]),
> + "could not expand call to %<__builtin_%s%> inline: "
> + "size must be constant", name);
> + else
> + error ("could not expand call to %<__builtin_%s%> inline: "
> + "size must be constant", name);
> + return false;
> + }
I think you want to use warning_at and error_at above... the first
argument to `warning' (and second to warning_at) is not a location but
an OPT_W* value. You should pass 0 to the opt argument in this case as
there is no -W option to handle this warning.
Also, I would not mention 'expand' in the error/warning message, as it
is a GCC internal concept. I would use perhaps "could not inline call
to %<__builtin_%s%>".
> + /* Alignment is a CONST_INT. */
> + gcc_assert (CONST_INT_P (operands[3]));
> +
> + rtx dst = operands[0];
> + rtx src = operands[1];
> + rtx size = operands[2];
> + unsigned HOST_WIDE_INT size_bytes = UINTVAL (size);
> + unsigned align = UINTVAL (operands[3]);
> + enum machine_mode mode;
> + switch (align)
> + {
> + case 1: mode = QImode; break;
> + case 2: mode = HImode; break;
> + case 4: mode = SImode; break;
> + case 8: mode = DImode; break;
> + default:
> + gcc_unreachable ();
> + }
> +
> + unsigned iters = size_bytes >> ceil_log2 (align);
> + unsigned remainder = size_bytes & (align - 1);
> +
> + int inc = GET_MODE_SIZE (mode);
> + rtx_code_label *fwd_label, *done_label;
> + if (is_move)
> + {
> + /* For memmove, be careful of overlap. It is not a concern for memcpy.
> + To handle overlap, we check (at runtime) if SRC < DST, and if so do
> + the move "backwards" starting from SRC + SIZE. */
> + fwd_label = gen_label_rtx ();
> + done_label = gen_label_rtx ();
> +
> + rtx dst_addr = copy_to_mode_reg (Pmode, XEXP (dst, 0));
> + rtx src_addr = copy_to_mode_reg (Pmode, XEXP (src, 0));
> + emit_cmp_and_jump_insns (src_addr, dst_addr, GEU, NULL_RTX, Pmode,
> + true, fwd_label, profile_probability::even ());
> +
> + /* Emit the "backwards" unrolled loop. */
> + emit_move_loop (src, dst, mode, size_bytes, -inc, iters, remainder);
> + emit_jump_insn (gen_jump (done_label));
> + emit_barrier ();
> +
> + emit_label (fwd_label);
> + }
> +
> + emit_move_loop (src, dst, mode, 0, inc, iters, remainder);
> +
> + if (is_move)
> + emit_label (done_label);
> +
> + return true;
> +}
> +
> /* Finally, build the GCC target. */
>
> struct gcc_target targetm = TARGET_INITIALIZER;
> diff --git a/gcc/config/bpf/bpf.md b/gcc/config/bpf/bpf.md
> index 50df1aaa3e2..ca677bc6b50 100644
> --- a/gcc/config/bpf/bpf.md
> +++ b/gcc/config/bpf/bpf.md
> @@ -627,4 +627,40 @@ (define_insn "ldabs<ldop>"
> "{ldabs<ldop>\t%0|r0 = *(<pldop> *) skb[%0]}"
> [(set_attr "type" "ld")])
>
> +;;; memmove and memcopy
> +
> +;; 0 is dst
> +;; 1 is src
> +;; 2 is size of copy in bytes
> +;; 3 is alignment
> +
> +(define_expand "cpymemdi"
> + [(match_operand:BLK 0 "memory_operand")
> + (match_operand:BLK 1 "memory_operand")
> + (match_operand:DI 2 "general_operand")
> + (match_operand:DI 3 "immediate_operand")]
> + ""
> +{
> + if (bpf_expand_cpymem (operands, false))
> + DONE;
> + FAIL;
> +})
> +
> +;; 0 is dst
> +;; 1 is src
> +;; 2 is size of copy in bytes
> +;; 3 is alignment
> +
> +(define_expand "movmemdi"
> + [(match_operand:BLK 0 "memory_operand")
> + (match_operand:BLK 1 "memory_operand")
> + (match_operand:DI 2 "general_operand")
> + (match_operand:DI 3 "immediate_operand")]
> + ""
> +{
> + if (bpf_expand_cpymem (operands, true))
> + DONE;
> + FAIL;
> +})
> +
> (include "atomic.md")
> diff --git a/gcc/testsuite/gcc.target/bpf/memcpy-1.c b/gcc/testsuite/gcc.target/bpf/memcpy-1.c
> new file mode 100644
> index 00000000000..6c9707f24e8
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/memcpy-1.c
> @@ -0,0 +1,26 @@
> +/* Ensure memcpy is expanded inline rather than emitting a libcall. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +struct context {
> + unsigned int data;
> + unsigned int data_end;
> + unsigned int data_meta;
> + unsigned int ingress;
> + unsigned int queue_index;
> + unsigned int egress;
> +};
> +
> +void
> +cpy_1(struct context *ctx)
> +{
> + void *data = (void *)(long)ctx->data;
> + char *dest;
> + dest = data;
> + dest += 16;
> +
> + __builtin_memcpy (dest, data, 8);
> +}
> +
> +/* { dg-final { scan-assembler-times "call" 0 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/memmove-1.c b/gcc/testsuite/gcc.target/bpf/memmove-1.c
> new file mode 100644
> index 00000000000..3b8ba82639e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/memmove-1.c
> @@ -0,0 +1,46 @@
> +/* Ensure memmove is expanded inline rather than emitting a libcall. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +struct context {
> + unsigned int data;
> + unsigned int data_end;
> + unsigned int data_meta;
> + unsigned int ingress;
> + unsigned int queue_index;
> + unsigned int egress;
> +};
> +
> +void
> +mov_1_nooverlap (struct context *ctx)
> +{
> + void *data = (void *)(long)ctx->data;
> + char *dest;
> + dest = data;
> + dest += 16;
> +
> + __builtin_memmove (dest, data, 12);
> +}
> +
> +void
> +mov_1_overlap (struct context *ctx)
> +{
> + void *data = (void *)(long)ctx->data;
> + char *dest;
> + dest = data;
> + dest += 4;
> +
> + __builtin_memmove (dest, data, 12);
> +}
> +
> +void
> +mov_1_arbitrary (struct context *ctx_a, struct context *ctx_b)
> +{
> + void *src = (void *)(long)ctx_a->data;
> + void *dst = (void *)(long)ctx_b->data;
> +
> + __builtin_memmove (dst, src, 12);
> +}
> +
> +/* { dg-final { scan-assembler-times "call" 0 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/memmove-2.c b/gcc/testsuite/gcc.target/bpf/memmove-2.c
> new file mode 100644
> index 00000000000..7fae96095a3
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/memmove-2.c
> @@ -0,0 +1,23 @@
> +/* Test that we error if memmove cannot be expanded inline. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +typedef unsigned int __u32;
> +
> +struct context {
> + unsigned int data;
> + unsigned int data_end;
> + unsigned int data_meta;
> +};
> +
> +void
> +mov_2_unsupported (struct context *ctx)
> +{
> + void *data = (void *)(long)ctx->data;
> + char *dest;
> + dest = data;
> + dest += 4;
> +
> + __builtin_memmove (dest, data, ctx->data_meta); /* { dg-error "could not expand" } */
> +}
On 2/20/24 12:37, Jose E. Marchesi wrote:
>
> Hi Faust.
>
>> +bool
>> +bpf_expand_cpymem (rtx *operands, bool is_move)
>> +{
>> + /* Size must be constant for this expansion to work. */
>> + if (!CONST_INT_P (operands[2]))
>> + {
>> + const char *name = is_move ? "memmove" : "memcpy";
>> + if (flag_building_libgcc)
>> + warning (RTL_LOCATION (operands[2]),
>> + "could not expand call to %<__builtin_%s%> inline: "
>> + "size must be constant", name);
>> + else
>> + error ("could not expand call to %<__builtin_%s%> inline: "
>> + "size must be constant", name);
>> + return false;
>> + }
>
> I think you want to use warning_at and error_at above... the first
> argument to `warning' (and second to warning_at) is not a location but
> an OPT_W* value. You should pass 0 to the opt argument in this case as
> there is no -W option to handle this warning.
Oops. Thanks.
After fixing the arguments, `warning' and `error' generally give better
messages than `warning_at' and `error_at' since the
RTL_LOCATION (operands[2]) seems to be NULL for most (all?) cases, which
causes the diagnostic message to refer only to the containing function.
The non-`_at' versions highlight the builtin call being expanded, which
is much nicer.
>
> Also, I would not mention 'expand' in the error/warning message, as it
> is a GCC internal concept. I would use perhaps "could not inline call
> to %<__builtin_%s%>".
OK.
>
>> + /* Alignment is a CONST_INT. */
>> + gcc_assert (CONST_INT_P (operands[3]));
>> +
>> + rtx dst = operands[0];
>> + rtx src = operands[1];
>> + rtx size = operands[2];
>> + unsigned HOST_WIDE_INT size_bytes = UINTVAL (size);
>> + unsigned align = UINTVAL (operands[3]);
>> + enum machine_mode mode;
>> + switch (align)
>> + {
>> + case 1: mode = QImode; break;
>> + case 2: mode = HImode; break;
>> + case 4: mode = SImode; break;
>> + case 8: mode = DImode; break;
>> + default:
>> + gcc_unreachable ();
>> + }
>> +
>> + unsigned iters = size_bytes >> ceil_log2 (align);
>> + unsigned remainder = size_bytes & (align - 1);
>> +
>> + int inc = GET_MODE_SIZE (mode);
>> + rtx_code_label *fwd_label, *done_label;
>> + if (is_move)
>> + {
>> + /* For memmove, be careful of overlap. It is not a concern for memcpy.
>> + To handle overlap, we check (at runtime) if SRC < DST, and if so do
>> + the move "backwards" starting from SRC + SIZE. */
>> + fwd_label = gen_label_rtx ();
>> + done_label = gen_label_rtx ();
>> +
>> + rtx dst_addr = copy_to_mode_reg (Pmode, XEXP (dst, 0));
>> + rtx src_addr = copy_to_mode_reg (Pmode, XEXP (src, 0));
>> + emit_cmp_and_jump_insns (src_addr, dst_addr, GEU, NULL_RTX, Pmode,
>> + true, fwd_label, profile_probability::even ());
>> +
>> + /* Emit the "backwards" unrolled loop. */
>> + emit_move_loop (src, dst, mode, size_bytes, -inc, iters, remainder);
>> + emit_jump_insn (gen_jump (done_label));
>> + emit_barrier ();
>> +
>> + emit_label (fwd_label);
>> + }
>> +
>> + emit_move_loop (src, dst, mode, 0, inc, iters, remainder);
>> +
>> + if (is_move)
>> + emit_label (done_label);
>> +
>> + return true;
>> +}
>> +
>> /* Finally, build the GCC target. */
>>
>> struct gcc_target targetm = TARGET_INITIALIZER;
>> diff --git a/gcc/config/bpf/bpf.md b/gcc/config/bpf/bpf.md
>> index 50df1aaa3e2..ca677bc6b50 100644
>> --- a/gcc/config/bpf/bpf.md
>> +++ b/gcc/config/bpf/bpf.md
>> @@ -627,4 +627,40 @@ (define_insn "ldabs<ldop>"
>> "{ldabs<ldop>\t%0|r0 = *(<pldop> *) skb[%0]}"
>> [(set_attr "type" "ld")])
>>
>> +;;; memmove and memcopy
>> +
>> +;; 0 is dst
>> +;; 1 is src
>> +;; 2 is size of copy in bytes
>> +;; 3 is alignment
>> +
>> +(define_expand "cpymemdi"
>> + [(match_operand:BLK 0 "memory_operand")
>> + (match_operand:BLK 1 "memory_operand")
>> + (match_operand:DI 2 "general_operand")
>> + (match_operand:DI 3 "immediate_operand")]
>> + ""
>> +{
>> + if (bpf_expand_cpymem (operands, false))
>> + DONE;
>> + FAIL;
>> +})
>> +
>> +;; 0 is dst
>> +;; 1 is src
>> +;; 2 is size of copy in bytes
>> +;; 3 is alignment
>> +
>> +(define_expand "movmemdi"
>> + [(match_operand:BLK 0 "memory_operand")
>> + (match_operand:BLK 1 "memory_operand")
>> + (match_operand:DI 2 "general_operand")
>> + (match_operand:DI 3 "immediate_operand")]
>> + ""
>> +{
>> + if (bpf_expand_cpymem (operands, true))
>> + DONE;
>> + FAIL;
>> +})
>> +
>> (include "atomic.md")
>> diff --git a/gcc/testsuite/gcc.target/bpf/memcpy-1.c b/gcc/testsuite/gcc.target/bpf/memcpy-1.c
>> new file mode 100644
>> index 00000000000..6c9707f24e8
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/bpf/memcpy-1.c
>> @@ -0,0 +1,26 @@
>> +/* Ensure memcpy is expanded inline rather than emitting a libcall. */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2" } */
>> +
>> +struct context {
>> + unsigned int data;
>> + unsigned int data_end;
>> + unsigned int data_meta;
>> + unsigned int ingress;
>> + unsigned int queue_index;
>> + unsigned int egress;
>> +};
>> +
>> +void
>> +cpy_1(struct context *ctx)
>> +{
>> + void *data = (void *)(long)ctx->data;
>> + char *dest;
>> + dest = data;
>> + dest += 16;
>> +
>> + __builtin_memcpy (dest, data, 8);
>> +}
>> +
>> +/* { dg-final { scan-assembler-times "call" 0 } } */
>> diff --git a/gcc/testsuite/gcc.target/bpf/memmove-1.c b/gcc/testsuite/gcc.target/bpf/memmove-1.c
>> new file mode 100644
>> index 00000000000..3b8ba82639e
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/bpf/memmove-1.c
>> @@ -0,0 +1,46 @@
>> +/* Ensure memmove is expanded inline rather than emitting a libcall. */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2" } */
>> +
>> +struct context {
>> + unsigned int data;
>> + unsigned int data_end;
>> + unsigned int data_meta;
>> + unsigned int ingress;
>> + unsigned int queue_index;
>> + unsigned int egress;
>> +};
>> +
>> +void
>> +mov_1_nooverlap (struct context *ctx)
>> +{
>> + void *data = (void *)(long)ctx->data;
>> + char *dest;
>> + dest = data;
>> + dest += 16;
>> +
>> + __builtin_memmove (dest, data, 12);
>> +}
>> +
>> +void
>> +mov_1_overlap (struct context *ctx)
>> +{
>> + void *data = (void *)(long)ctx->data;
>> + char *dest;
>> + dest = data;
>> + dest += 4;
>> +
>> + __builtin_memmove (dest, data, 12);
>> +}
>> +
>> +void
>> +mov_1_arbitrary (struct context *ctx_a, struct context *ctx_b)
>> +{
>> + void *src = (void *)(long)ctx_a->data;
>> + void *dst = (void *)(long)ctx_b->data;
>> +
>> + __builtin_memmove (dst, src, 12);
>> +}
>> +
>> +/* { dg-final { scan-assembler-times "call" 0 } } */
>> diff --git a/gcc/testsuite/gcc.target/bpf/memmove-2.c b/gcc/testsuite/gcc.target/bpf/memmove-2.c
>> new file mode 100644
>> index 00000000000..7fae96095a3
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/bpf/memmove-2.c
>> @@ -0,0 +1,23 @@
>> +/* Test that we error if memmove cannot be expanded inline. */
>> +
>> +/* { dg-do compile } */
>> +/* { dg-options "-O2" } */
>> +
>> +typedef unsigned int __u32;
>> +
>> +struct context {
>> + unsigned int data;
>> + unsigned int data_end;
>> + unsigned int data_meta;
>> +};
>> +
>> +void
>> +mov_2_unsupported (struct context *ctx)
>> +{
>> + void *data = (void *)(long)ctx->data;
>> + char *dest;
>> + dest = data;
>> + dest += 4;
>> +
>> + __builtin_memmove (dest, data, ctx->data_meta); /* { dg-error "could not expand" } */
>> +}
@@ -35,4 +35,6 @@ const char *bpf_add_core_reloc (rtx *operands, const char *templ);
class gimple_opt_pass;
gimple_opt_pass *make_pass_lower_bpf_core (gcc::context *ctxt);
+bool bpf_expand_cpymem (rtx *, bool);
+
#endif /* ! GCC_BPF_PROTOS_H */
@@ -1184,6 +1184,122 @@ bpf_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size,
#define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
bpf_use_by_pieces_infrastructure_p
+/* Helper for bpf_expand_cpymem. Emit an unrolled loop moving the bytes
+ from SRC to DST. */
+
+static void
+emit_move_loop (rtx src, rtx dst, machine_mode mode, int offset, int inc,
+ unsigned iters, unsigned remainder)
+{
+ rtx reg = gen_reg_rtx (mode);
+
+ /* First copy in chunks as large as alignment permits. */
+ for (unsigned int i = 0; i < iters; i++)
+ {
+ emit_move_insn (reg, adjust_address (src, mode, offset));
+ emit_move_insn (adjust_address (dst, mode, offset), reg);
+ offset += inc;
+ }
+
+ /* Handle remaining bytes which might be smaller than the chunks
+ used above. */
+ if (remainder & 4)
+ {
+ emit_move_insn (reg, adjust_address (src, SImode, offset));
+ emit_move_insn (adjust_address (dst, SImode, offset), reg);
+ offset += (inc < 0 ? -4 : 4);
+ remainder -= 4;
+ }
+ if (remainder & 2)
+ {
+ emit_move_insn (reg, adjust_address (src, HImode, offset));
+ emit_move_insn (adjust_address (dst, HImode, offset), reg);
+ offset += (inc < 0 ? -2 : 2);
+ remainder -= 2;
+ }
+ if (remainder & 1)
+ {
+ emit_move_insn (reg, adjust_address (src, QImode, offset));
+ emit_move_insn (adjust_address (dst, QImode, offset), reg);
+ }
+}
+
+/* Expand cpymem/movmem, as from __builtin_memcpy/memmove.
+ OPERANDS are the same as the cpymem/movmem patterns.
+ IS_MOVE is true if this is a memmove, false for memcpy.
+ Return true if we successfully expanded, or false if we cannot
+ and must punt to a libcall. */
+
+bool
+bpf_expand_cpymem (rtx *operands, bool is_move)
+{
+ /* Size must be constant for this expansion to work. */
+ if (!CONST_INT_P (operands[2]))
+ {
+ const char *name = is_move ? "memmove" : "memcpy";
+ if (flag_building_libgcc)
+ warning (RTL_LOCATION (operands[2]),
+ "could not expand call to %<__builtin_%s%> inline: "
+ "size must be constant", name);
+ else
+ error ("could not expand call to %<__builtin_%s%> inline: "
+ "size must be constant", name);
+ return false;
+ }
+
+ /* Alignment is a CONST_INT. */
+ gcc_assert (CONST_INT_P (operands[3]));
+
+ rtx dst = operands[0];
+ rtx src = operands[1];
+ rtx size = operands[2];
+ unsigned HOST_WIDE_INT size_bytes = UINTVAL (size);
+ unsigned align = UINTVAL (operands[3]);
+ enum machine_mode mode;
+ switch (align)
+ {
+ case 1: mode = QImode; break;
+ case 2: mode = HImode; break;
+ case 4: mode = SImode; break;
+ case 8: mode = DImode; break;
+ default:
+ gcc_unreachable ();
+ }
+
+ unsigned iters = size_bytes >> ceil_log2 (align);
+ unsigned remainder = size_bytes & (align - 1);
+
+ int inc = GET_MODE_SIZE (mode);
+ rtx_code_label *fwd_label, *done_label;
+ if (is_move)
+ {
+ /* For memmove, be careful of overlap. It is not a concern for memcpy.
+ To handle overlap, we check (at runtime) if SRC < DST, and if so do
+ the move "backwards" starting from SRC + SIZE. */
+ fwd_label = gen_label_rtx ();
+ done_label = gen_label_rtx ();
+
+ rtx dst_addr = copy_to_mode_reg (Pmode, XEXP (dst, 0));
+ rtx src_addr = copy_to_mode_reg (Pmode, XEXP (src, 0));
+ emit_cmp_and_jump_insns (src_addr, dst_addr, GEU, NULL_RTX, Pmode,
+ true, fwd_label, profile_probability::even ());
+
+ /* Emit the "backwards" unrolled loop. */
+ emit_move_loop (src, dst, mode, size_bytes, -inc, iters, remainder);
+ emit_jump_insn (gen_jump (done_label));
+ emit_barrier ();
+
+ emit_label (fwd_label);
+ }
+
+ emit_move_loop (src, dst, mode, 0, inc, iters, remainder);
+
+ if (is_move)
+ emit_label (done_label);
+
+ return true;
+}
+
/* Finally, build the GCC target. */
struct gcc_target targetm = TARGET_INITIALIZER;
@@ -627,4 +627,40 @@ (define_insn "ldabs<ldop>"
"{ldabs<ldop>\t%0|r0 = *(<pldop> *) skb[%0]}"
[(set_attr "type" "ld")])
+;;; memmove and memcopy
+
+;; 0 is dst
+;; 1 is src
+;; 2 is size of copy in bytes
+;; 3 is alignment
+
+(define_expand "cpymemdi"
+ [(match_operand:BLK 0 "memory_operand")
+ (match_operand:BLK 1 "memory_operand")
+ (match_operand:DI 2 "general_operand")
+ (match_operand:DI 3 "immediate_operand")]
+ ""
+{
+ if (bpf_expand_cpymem (operands, false))
+ DONE;
+ FAIL;
+})
+
+;; 0 is dst
+;; 1 is src
+;; 2 is size of copy in bytes
+;; 3 is alignment
+
+(define_expand "movmemdi"
+ [(match_operand:BLK 0 "memory_operand")
+ (match_operand:BLK 1 "memory_operand")
+ (match_operand:DI 2 "general_operand")
+ (match_operand:DI 3 "immediate_operand")]
+ ""
+{
+ if (bpf_expand_cpymem (operands, true))
+ DONE;
+ FAIL;
+})
+
(include "atomic.md")
new file mode 100644
@@ -0,0 +1,26 @@
+/* Ensure memcpy is expanded inline rather than emitting a libcall. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct context {
+ unsigned int data;
+ unsigned int data_end;
+ unsigned int data_meta;
+ unsigned int ingress;
+ unsigned int queue_index;
+ unsigned int egress;
+};
+
+void
+cpy_1(struct context *ctx)
+{
+ void *data = (void *)(long)ctx->data;
+ char *dest;
+ dest = data;
+ dest += 16;
+
+ __builtin_memcpy (dest, data, 8);
+}
+
+/* { dg-final { scan-assembler-times "call" 0 } } */
new file mode 100644
@@ -0,0 +1,46 @@
+/* Ensure memmove is expanded inline rather than emitting a libcall. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct context {
+ unsigned int data;
+ unsigned int data_end;
+ unsigned int data_meta;
+ unsigned int ingress;
+ unsigned int queue_index;
+ unsigned int egress;
+};
+
+void
+mov_1_nooverlap (struct context *ctx)
+{
+ void *data = (void *)(long)ctx->data;
+ char *dest;
+ dest = data;
+ dest += 16;
+
+ __builtin_memmove (dest, data, 12);
+}
+
+void
+mov_1_overlap (struct context *ctx)
+{
+ void *data = (void *)(long)ctx->data;
+ char *dest;
+ dest = data;
+ dest += 4;
+
+ __builtin_memmove (dest, data, 12);
+}
+
+void
+mov_1_arbitrary (struct context *ctx_a, struct context *ctx_b)
+{
+ void *src = (void *)(long)ctx_a->data;
+ void *dst = (void *)(long)ctx_b->data;
+
+ __builtin_memmove (dst, src, 12);
+}
+
+/* { dg-final { scan-assembler-times "call" 0 } } */
new file mode 100644
@@ -0,0 +1,23 @@
+/* Test that we error if memmove cannot be expanded inline. */
+
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef unsigned int __u32;
+
+struct context {
+ unsigned int data;
+ unsigned int data_end;
+ unsigned int data_meta;
+};
+
+void
+mov_2_unsupported (struct context *ctx)
+{
+ void *data = (void *)(long)ctx->data;
+ char *dest;
+ dest = data;
+ dest += 4;
+
+ __builtin_memmove (dest, data, ctx->data_meta); /* { dg-error "could not expand" } */
+}