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43 #include "arch/arm/decoder.hh"
44 #include "arch/arm/isa_traits.hh"
45 #include "arch/arm/utility.hh"
46 #include "base/trace.hh"
47 #include "debug/Decoder.hh"
52 GenericISA::BasicDecodeCache
Decoder::defaultCache
;
57 // emi is typically ready, with some caveats below...
63 emi
.sevenAndFour
= bits(data
, 7) && bits(data
, 4);
64 emi
.isMisc
= (bits(data
, 24, 23) == 0x2 &&
68 DPRINTF(Decoder
, "Arm inst: %#x.\n", (uint64_t)emi
);
70 uint16_t word
= (data
>> (offset
* 8));
72 // A 32 bit thumb inst is half collected.
73 emi
.instBits
= emi
.instBits
| word
;
76 DPRINTF(Decoder
, "Second half of 32 bit Thumb: %#x.\n",
79 uint16_t highBits
= word
& 0xF800;
80 if (highBits
== 0xE800 || highBits
== 0xF000 ||
82 // The start of a 32 bit thumb inst.
85 // We've got the whole thing.
86 emi
.instBits
= (data
>> 16) | (data
<< 16);
87 DPRINTF(Decoder
, "All of 32 bit Thumb: %#x.\n",
91 // We only have the first half word.
93 "First half of 32 bit Thumb.\n");
94 emi
.instBits
= (uint32_t)word
<< 16;
101 // A 16 bit thumb inst.
104 // Set the condition code field artificially.
105 emi
.condCode
= COND_UC
;
106 DPRINTF(Decoder
, "16 bit Thumb: %#x.\n",
108 if (bits(word
, 15, 8) == 0xbf &&
109 bits(word
, 3, 0) != 0x0) {
111 itBits
= bits(word
, 7, 0);
113 "IT detected, cond = %#x, mask = %#x\n",
114 itBits
.cond
, itBits
.mask
);
121 //Use this to give data to the decoder. This should be used
122 //when there is control flow.
124 Decoder::moreBytes(const PCState
&pc
, Addr fetchPC
, MachInst inst
)
127 offset
= (fetchPC
>= pc
.instAddr()) ? 0 : pc
.instAddr() - fetchPC
;
128 emi
.thumb
= pc
.thumb();
129 emi
.aarch64
= pc
.aarch64();
130 emi
.fpscrLen
= fpscrLen
;
131 emi
.fpscrStride
= fpscrStride
;