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tcg: Improve the alignment check infrastructure

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Some architectures (e.g. ARMv8) need the address which is aligned
to a size more than the size of the memory access.
To support such check it's enough the current costless alignment
check implementation in QEMU, but we need to support
an alignment size specifying.

Signed-off-by: Sergey Sorokin <afarallax@yandex.ru>
Message-Id: <1466705806-679898-1-git-send-email-afarallax@yandex.ru>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Assert in tcg_canonicalize_memop.  Leave get_alignment_bits
available for, though unused by, user-mode.  Retain logging difference
based on ALIGNED_ONLY.]
This commit is contained in:
Sergey Sorokin 2016-06-23 21:16:46 +03:00 • committed by Richard Henderson
parent 59d7c14eef
commit 1f00b27f17
9 changed files with 159 additions and 108 deletions
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9
tcg/aarch64/tcg-target.inc.c
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@ -1081,19 +1081,20 @@ static void tcg_out_tlb_read(TCGContext *s, TCGReg addr_reg, TCGMemOp opc,
int tlb_offset = is_read ?
offsetof(CPUArchState, tlb_table[mem_index][0].addr_read)
: offsetof(CPUArchState, tlb_table[mem_index][0].addr_write);
int s_mask = (1 << (opc & MO_SIZE)) - 1;
int a_bits = get_alignment_bits(opc);
TCGReg base = TCG_AREG0, x3;
uint64_t tlb_mask;
/* For aligned accesses, we check the first byte and include the alignment
bits within the address. For unaligned access, we check that we don't
cross pages using the address of the last byte of the access. */
if ((opc & MO_AMASK) == MO_ALIGN || s_mask == 0) {
tlb_mask = TARGET_PAGE_MASK | s_mask;
if (a_bits >= 0) {
/* A byte access or an alignment check required */
tlb_mask = TARGET_PAGE_MASK | ((1 << a_bits) - 1);
x3 = addr_reg;
} else {
tcg_out_insn(s, 3401, ADDI, TARGET_LONG_BITS == 64,
TCG_REG_X3, addr_reg, s_mask);
TCG_REG_X3, addr_reg, (1 << (opc & MO_SIZE)) - 1);
tlb_mask = TARGET_PAGE_MASK;
x3 = TCG_REG_X3;
}