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author | Richard Henderson <rth@twiddle.net> | 2013-08-28 14:40:52 -0700 |
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committer | Richard Henderson <rth@twiddle.net> | 2013-10-01 10:20:33 -0700 |
commit | f2488736371ae902f345cf9270d141f0a6797731 (patch) | |
tree | 62f0462125497b8c198ac649e7137f084bb4de97 /tcg/arm | |
parent | e5e2e4a74b75b41f72e1e3b3bac8c2a6b02896c2 (diff) | |
download | qemu-f2488736371ae902f345cf9270d141f0a6797731.zip qemu-f2488736371ae902f345cf9270d141f0a6797731.tar.gz qemu-f2488736371ae902f345cf9270d141f0a6797731.tar.bz2 |
tcg-arm: Use QEMU_BUILD_BUG_ON to verify constraints on tlb
One of the two constraints we already checked via #if, but
the tlb offset distance was only checked at runtime.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'tcg/arm')
-rw-r--r-- | tcg/arm/tcg-target.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index f953f4e..1f7bbe1 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -1163,6 +1163,15 @@ static TCGReg tcg_out_arg_reg64(TCGContext *s, TCGReg argreg, #define TLB_SHIFT (CPU_TLB_ENTRY_BITS + CPU_TLB_BITS) +/* We're expecting to use an 8-bit immediate and to mask. */ +QEMU_BUILD_BUG_ON(CPU_TLB_BITS > 8); + +/* We're expecting to use an 8-bit immediate add + 8-bit ldrd offset. + Using the offset of the second entry in the last tlb table ensures + that we can index all of the elements of the first entry. */ +QEMU_BUILD_BUG_ON(offsetof(CPUArchState, tlb_table[NB_MMU_MODES - 1][1]) + > 0xffff); + /* Load and compare a TLB entry, leaving the flags set. Leaves R2 pointing to the tlb entry. Clobbers R1 and TMP. */ @@ -1190,14 +1199,10 @@ static void tcg_out_tlb_read(TCGContext *s, TCGReg addrlo, TCGReg addrhi, * ldr r0, [r2, r0]! (3) * cmp r0, tmp (4) */ -# if CPU_TLB_BITS > 8 -# error -# endif tcg_out_dat_reg(s, COND_AL, ARITH_MOV, TCG_REG_TMP, 0, addrlo, SHIFT_IMM_LSR(TARGET_PAGE_BITS)); - /* We assume that the offset is contained within 16 bits. */ - assert((tlb_offset & ~0xffff) == 0); + /* We checked that the offset is contained within 16 bits above. */ if (tlb_offset > 0xff) { tcg_out_dat_imm(s, COND_AL, ARITH_ADD, TCG_REG_R2, base, (24 << 7) | (tlb_offset >> 8)); |