@@ -67,6 +67,8 @@ along with GCC; see the file COPYING3. If not see
#include "tree-vector-builder.h"
#include "tree-ssa-strlen.h"
#include "varasm.h"
+#include "memmodel.h"
+#include "optabs.h"
enum strlen_range_kind {
/* Compute the exact constant string length. */
@@ -957,14 +959,17 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
= build_int_cst (build_pointer_type_for_mode (char_type_node,
ptr_mode, true), 0);
- /* If we can perform the copy efficiently with first doing all loads
- and then all stores inline it that way. Currently efficiently
- means that we can load all the memory into a single integer
- register which is what MOVE_MAX gives us. */
+ /* If we can perform the copy efficiently with first doing all loads and
+ then all stores inline it that way. Currently efficiently means that
+ we can load all the memory with a single set operation and that the
+ total size is less than MOVE_MAX * MOVE_RATIO. */
src_align = get_pointer_alignment (src);
dest_align = get_pointer_alignment (dest);
if (tree_fits_uhwi_p (len)
- && compare_tree_int (len, MOVE_MAX) <= 0
+ && (compare_tree_int
+ (len, (MOVE_MAX
+ * MOVE_RATIO (optimize_function_for_size_p (cfun))))
+ <= 0)
/* FIXME: Don't transform copies from strings with known length.
Until GCC 9 this prevented a case in gcc.dg/strlenopt-8.c
from being handled, and the case was XFAILed for that reason.
@@ -1000,6 +1005,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
if (type
&& is_a <scalar_int_mode> (TYPE_MODE (type), &mode)
&& GET_MODE_SIZE (mode) * BITS_PER_UNIT == ilen * 8
+ && have_insn_for (SET, mode)
/* If the destination pointer is not aligned we must be able
to emit an unaligned store. */
&& (dest_align >= GET_MODE_ALIGNMENT (mode)
The current restriction on folding memcpy to a single element of size MOVE_MAX is excessively cautious on most machines and limits some significant further optimizations. So relax the restriction provided the copy size does not exceed MOVE_MAX * MOVE_RATIO and that a SET insn exists for moving the value into machine registers. Note that there were already checks in place for having misaligned move operations when one or more of the operands were unaligned. On Arm this now permits optimizing uint64_t bar64(const uint8_t *rData1) { uint64_t buffer; memcpy(&buffer, rData1, sizeof(buffer)); return buffer; } from ldr r2, [r0] @ unaligned sub sp, sp, #8 ldr r3, [r0, #4] @ unaligned strd r2, [sp] ldrd r0, [sp] add sp, sp, #8 to mov r3, r0 ldr r0, [r0] @ unaligned ldr r1, [r3, #4] @ unaligned PR target/102125 - (ARM Cortex-M3 and newer) missed optimization. memcpy not needed operations gcc/ChangeLog: PR target/102125 * gimple-fold.c (gimple_fold_builtin_memory_op): Allow folding memcpy if the size is not more than MOVE_MAX * MOVE_RATIO. --- gcc/gimple-fold.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)