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tcg: Support arbitrary size + alignment

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Previously we allowed fully unaligned operations, but not operations
that are aligned but with less alignment than the operation size.

In addition, arm32, ia64, mips, and sparc had been omitted from the
previous overalignment patch, which would have led to that alignment
being enforced.

Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2016-07-14 12:43:06 -07:00
parent ebc231d7da
commit 85aa80813d
10 changed files with 128 additions and 112 deletions
Download patch file Download diff file Expand all files Collapse all files

19
tcg/arm/tcg-target.inc.c
View file

@ -1168,7 +1168,7 @@ QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table[NB_MMU_MODES - 1][1])
containing the addend of the tlb entry. Clobbers R0, R1, R2, TMP. */
static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
TCGMemOp s_bits, int mem_index, bool is_load)
TCGMemOp opc, int mem_index, bool is_load)
{
TCGReg base = TCG_AREG0;
int cmp_off =
@ -1176,6 +1176,8 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
? offsetof(CPUArchState, tlb_table[mem_index][0].addr_read)
: offsetof(CPUArchState, tlb_table[mem_index][0].addr_write));
int add_off = offsetof(CPUArchState, tlb_table[mem_index][0].addend);
unsigned s_bits = opc & MO_SIZE;
unsigned a_bits = get_alignment_bits(opc);
/* Should generate something like the following:
* shr tmp, addrlo, #TARGET_PAGE_BITS (1)
@ -1216,10 +1218,13 @@ static TCGReg tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
}
}
/* Check alignment. */
if (s_bits) {
tcg_out_dat_imm(s, COND_AL, ARITH_TST,
0, addrlo, (1 << s_bits) - 1);
/* Check alignment. We don't support inline unaligned acceses,
but we can easily support overalignment checks. */
if (a_bits < s_bits) {
a_bits = s_bits;
}
if (a_bits) {
tcg_out_dat_imm(s, COND_AL, ARITH_TST, 0, addrlo, (1 << a_bits) - 1);
}
/* Load the tlb addend. */
@ -1499,7 +1504,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is64)
#ifdef CONFIG_SOFTMMU
mem_index = get_mmuidx(oi);
addend = tcg_out_tlb_read(s, addrlo, addrhi, opc & MO_SIZE, mem_index, 1);
addend = tcg_out_tlb_read(s, addrlo, addrhi, opc, mem_index, 1);
/* This a conditional BL only to load a pointer within this opcode into LR
for the slow path. We will not be using the value for a tail call. */
@ -1630,7 +1635,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is64)
#ifdef CONFIG_SOFTMMU
mem_index = get_mmuidx(oi);
addend = tcg_out_tlb_read(s, addrlo, addrhi, opc & MO_SIZE, mem_index, 0);
addend = tcg_out_tlb_read(s, addrlo, addrhi, opc, mem_index, 0);
tcg_out_qemu_st_index(s, COND_EQ, opc, datalo, datahi, addrlo, addend);