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| author | Jiong Wang <jiong.wang@arm.com> | 2014-08-01 15:17:03 +0000 |
|---|---|---|
| committer | Jiong Wang <jiwang@gcc.gnu.org> | 2014-08-01 15:17:03 +0000 |
| commit | 15c0c5c9125691e33a0763e45bf48406ffc2edc8 (patch) | |
| tree | 623d83c0d76db500b4903d27890d31412a9f0b56 /gcc/config/aarch64 | |
| parent | 4470747882d347fc2da36479aec26fc3d7c938f7 (diff) | |
| download | gcc-15c0c5c9125691e33a0763e45bf48406ffc2edc8.zip gcc-15c0c5c9125691e33a0763e45bf48406ffc2edc8.tar.gz gcc-15c0c5c9125691e33a0763e45bf48406ffc2edc8.tar.bz2 | |
[AArch64] Improve TARGET_LEGITIMIZE_ADDRESS_P hook
currently, aarch64 LEGITIMIZE_ADDRESS_P hook will reject all "reg + offset"
address given "offset" is beyond supported range.
while this may be too strict. we should honor the "strict_p" parameter in the
hook. before reload, we accept all offset if it's a frame access, because the
offset may change during later register elimination.
the early reject of "reg + offset" may cause extra registers created, and if
that register live range is across function invoking then callee saved reg
needed, thus introduce extra reg save/restore also.
give a simple example as:
int
test15 (void)
{
unsigned char a[480];
initialize_array (a, 480);
if (a[0] == 0x10)
return 1;
return 0;
}
.S before the patch
(-O2 -fPIC)
===
test15:
sub sp, sp, #480
mov w1, 480
stp x29, x30, [sp, -32]!
add x29, sp, 0
str x19, [sp, 16]
add x19, x29, 32
mov x0, x19
bl initialize_array
ldrb w0, [x19]
ldr x19, [sp, 16]
ldp x29, x30, [sp], 32
cmp w0, 16
cset w0, eq
add sp, sp, 480
ret
.S after the patch
===
test15:
stp x29, x30, [sp, -496]!
mov w1, 480
add x29, sp, 0
add x0, x29, 16
bl initialize_array
ldrb w0, [x29, 16]
ldp x29, x30, [sp], 496
cmp w0, 16
cset w0, eq
ret
gcc/
* config/aarch64/aarch64.c (aarch64_classify_address): Accept all offset for
frame access when strict_p is false.
gcc/testsuite
* gcc.target/aarch64/legitimize_stack_var_before_reload_1.c: New testcase.
From-SVN: r213488
Diffstat (limited to 'gcc/config/aarch64')
| -rw-r--r-- | gcc/config/aarch64/aarch64.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index d3f2adb..7e135a1 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -3248,6 +3248,21 @@ aarch64_classify_address (struct aarch64_address_info *info, case PLUS: op0 = XEXP (x, 0); op1 = XEXP (x, 1); + + if (! strict_p + && GET_CODE (op0) == REG + && (op0 == virtual_stack_vars_rtx + || op0 == frame_pointer_rtx + || op0 == arg_pointer_rtx) + && GET_CODE (op1) == CONST_INT) + { + info->type = ADDRESS_REG_IMM; + info->base = op0; + info->offset = op1; + + return true; + } + if (GET_MODE_SIZE (mode) != 0 && CONST_INT_P (op1) && aarch64_base_register_rtx_p (op0, strict_p)) |