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https://github.com/c64scene-ar/llvm-6502.git
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The long encoding for Thumb2 unconditional branches is broken. Additionally, there is no range checking for target operands; as such for instructions originating in assembly code, only short Thumb encodings are generated, regardless of the bitsize needed for the offset. Adding range checking is non trivial due to the representation of Thumb branch instructions. There is no true difference between conditional and unconditional branches in terms of operands and syntax - even unconditional branches have a predicate which is expected to match that of the IT block they are in. Yet, the encodings and the permitted size of the offset differ. Due to this, for any mnemonic there are really 4 encodings to choose for. The problem cannot be handled in the parser alone or by manipulating td files. Because the parser builds first a set of match candidates and then checks them one by one, whatever tablegen-only solution might be found will ultimately be dependent of the parser's evaluation order. What's worse is that due to the fact that all branches have the same syntax and the same kinds of operands, that order is governed by the lexicographical ordering of the names of operand classes... To circumvent all this, any necessary disambiguation is added to the instruction validation pass. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188067 91177308-0d34-0410-b5e6-96231b3b80d8
287 lines
12 KiB
ArmAsm
287 lines
12 KiB
ArmAsm
@ RUN: llvm-mc -triple=thumbv7-apple-darwin -mcpu=cortex-a8 -show-encoding < %s | FileCheck %s
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@------------------------------------------------------------------------------
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@ unconditional branches accept narrow suffix and encode to short encodings
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@------------------------------------------------------------------------------
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b.n #-2048
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b.n #2046
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@ CHECK: b #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: b #2046 @ encoding: [0xff,0xe3]
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@------------------------------------------------------------------------------
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@ unconditional branches accept wide suffix and encode to wide encodings
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@------------------------------------------------------------------------------
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b.w #-2048
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b.w #2046
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b.w #-1677216
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b.w #1677214
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@ CHECK: b.w #-2048 @ encoding: [0xff,0xf7,0x00,0xbc]
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@ CHECK: b.w #2046 @ encoding: [0x00,0xf0,0xff,0xbb]
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@ CHECK: b.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: b.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ unconditional branches without width suffix encode depending of offset size
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@------------------------------------------------------------------------------
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b #-2048
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b #2046
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b #-2050
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b #2048
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b #-1677216
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b #1677214
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@ CHECK: b #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: b #2046 @ encoding: [0xff,0xe3]
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@ CHECK: b.w #-2050 @ encoding: [0xff,0xf7,0xff,0xbb]
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@ CHECK: b.w #2048 @ encoding: [0x00,0xf0,0x00,0xbc]
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@ CHECK: b.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: b.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ unconditional branches with width narrow suffix in IT block
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@------------------------------------------------------------------------------
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it eq
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beq.n #-2048
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it ne
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bne.n #-2046
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@ CHECK: it eq @ encoding: [0x08,0xbf]
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@ CHECK: beq #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: it ne @ encoding: [0x18,0xbf]
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@ CHECK: bne #-2046 @ encoding: [0x01,0xe4]
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@------------------------------------------------------------------------------
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@ unconditional branches with wide suffix in IT block
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@------------------------------------------------------------------------------
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it gt
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bgt.w #-2048
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it le
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ble.w #2046
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it ge
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bge.w #-1677216
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it lt
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blt.w #1677214
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@ CHECK: it gt @ encoding: [0xc8,0xbf]
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@ CHECK: bgt.w #-2048 @ encoding: [0xff,0xf7,0x00,0xbc]
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@ CHECK: it le @ encoding: [0xd8,0xbf]
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@ CHECK: ble.w #2046 @ encoding: [0x00,0xf0,0xff,0xbb]
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@ CHECK: it ge @ encoding: [0xa8,0xbf]
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@ CHECK: bge.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: it lt @ encoding: [0xb8,0xbf]
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@ CHECK: blt.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ conditional branches accept narrow suffix and encode to short encodings
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@------------------------------------------------------------------------------
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beq.n #-256
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bne.n #254
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@ CHECK: beq #-256 @ encoding: [0x80,0xd0]
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@ CHECK: bne #254 @ encoding: [0x7f,0xd1]
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@------------------------------------------------------------------------------
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@ unconditional branches accept wide suffix and encode to wide encodings
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@------------------------------------------------------------------------------
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bmi.w #-256
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bne.w #254
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blt.w #-1048576
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bge.w #1048574
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@ CHECK: bmi.w #-256 @ encoding: [0x3f,0xf5,0x80,0xaf]
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@ CHECK: bne.w #254 @ encoding: [0x40,0xf0,0x7f,0x80]
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@ CHECK: blt.w #-1048576 @ encoding: [0xc0,0xf6,0x00,0x80]
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@ CHECK: bge.w #1048574 @ encoding: [0xbf,0xf2,0xff,0xaf]
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@------------------------------------------------------------------------------
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@ unconditional branches without width suffix encode depending of offset size
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@------------------------------------------------------------------------------
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bne #-256
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bgt #254
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bne #-258
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bgt #256
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bne #-1048576
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bgt #1048574
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@ CHECK: bne #-256 @ encoding: [0x80,0xd1]
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@ CHECK: bgt #254 @ encoding: [0x7f,0xdc]
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@ CHECK: bne.w #-258 @ encoding: [0x7f,0xf4,0x7f,0xaf]
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@ CHECK: bgt.w #256 @ encoding: [0x00,0xf3,0x80,0x80]
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@ CHECK: bne.w #-1048576 @ encoding: [0x40,0xf4,0x00,0x80]
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@ CHECK: bgt.w #1048574 @ encoding: [0x3f,0xf3,0xff,0xaf]
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@------------------------------------------------------------------------------
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@ same branch insturction encoding to conditional or unconditional depending
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@ on whether it is in an IT block or not
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@------------------------------------------------------------------------------
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it eq
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addeq r0, r1
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bne #128
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@ CHECK: it eq @ encoding: [0x08,0xbf]
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@ CHECK: addeq r0, r1 @ encoding: [0x08,0x44]
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@ CHECK: bne #128 @ encoding: [0x40,0xd1]
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ite eq
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addeq r0, r1
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bne #128
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@ CHECK: ite eq @ encoding: [0x0c,0xbf]
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@ CHECK: addeq r0, r1 @ encoding: [0x08,0x44]
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@ CHECK: bne #128 @ encoding: [0x40,0xe0]
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@ RUN: llvm-mc -triple=thumbv7-apple-darwin -mcpu=cortex-a8 -show-encoding < %s | FileCheck %s
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@------------------------------------------------------------------------------
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@ unconditional branches accept narrow suffix and encode to short encodings
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@------------------------------------------------------------------------------
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b.n #-2048
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b.n #2046
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@ CHECK: b #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: b #2046 @ encoding: [0xff,0xe3]
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@------------------------------------------------------------------------------
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@ unconditional branches accept wide suffix and encode to wide encodings
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@------------------------------------------------------------------------------
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b.w #-2048
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b.w #2046
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b.w #-1677216
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b.w #1677214
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@ CHECK: b.w #-2048 @ encoding: [0xff,0xf7,0x00,0xbc]
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@ CHECK: b.w #2046 @ encoding: [0x00,0xf0,0xff,0xbb]
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@ CHECK: b.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: b.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ unconditional branches without width suffix encode depending of offset size
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@------------------------------------------------------------------------------
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b #-2048
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b #2046
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b #-2050
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b #2048
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b #-1677216
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b #1677214
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@ CHECK: b #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: b #2046 @ encoding: [0xff,0xe3]
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@ CHECK: b.w #-2050 @ encoding: [0xff,0xf7,0xff,0xbb]
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@ CHECK: b.w #2048 @ encoding: [0x00,0xf0,0x00,0xbc]
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@ CHECK: b.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: b.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ unconditional branches with width narrow suffix in IT block
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@------------------------------------------------------------------------------
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it eq
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beq.n #-2048
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it ne
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bne.n #-2046
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@ CHECK: it eq @ encoding: [0x08,0xbf]
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@ CHECK: beq #-2048 @ encoding: [0x00,0xe4]
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@ CHECK: it ne @ encoding: [0x18,0xbf]
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@ CHECK: bne #-2046 @ encoding: [0x01,0xe4]
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@------------------------------------------------------------------------------
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@ unconditional branches with wide suffix in IT block
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@------------------------------------------------------------------------------
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it gt
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bgt.w #-2048
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it le
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ble.w #2046
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it ge
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bge.w #-1677216
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it lt
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blt.w #1677214
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@ CHECK: it gt @ encoding: [0xc8,0xbf]
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@ CHECK: bgt.w #-2048 @ encoding: [0xff,0xf7,0x00,0xbc]
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@ CHECK: it le @ encoding: [0xd8,0xbf]
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@ CHECK: ble.w #2046 @ encoding: [0x00,0xf0,0xff,0xbb]
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@ CHECK: it ge @ encoding: [0xa8,0xbf]
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@ CHECK: bge.w #-1677216 @ encoding: [0x66,0xf6,0x30,0xbc]
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@ CHECK: it lt @ encoding: [0xb8,0xbf]
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@ CHECK: blt.w #1677214 @ encoding: [0x99,0xf1,0xcf,0xbb]
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@------------------------------------------------------------------------------
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@ conditional branches accept narrow suffix and encode to short encodings
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@------------------------------------------------------------------------------
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beq.n #-256
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bne.n #254
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@ CHECK: beq #-256 @ encoding: [0x80,0xd0]
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@ CHECK: bne #254 @ encoding: [0x7f,0xd1]
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@------------------------------------------------------------------------------
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@ unconditional branches accept wide suffix and encode to wide encodings
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@------------------------------------------------------------------------------
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bmi.w #-256
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bne.w #254
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blt.w #-1048576
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bge.w #1048574
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@ CHECK: bmi.w #-256 @ encoding: [0x3f,0xf5,0x80,0xaf]
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@ CHECK: bne.w #254 @ encoding: [0x40,0xf0,0x7f,0x80]
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@ CHECK: blt.w #-1048576 @ encoding: [0xc0,0xf6,0x00,0x80]
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@ CHECK: bge.w #1048574 @ encoding: [0xbf,0xf2,0xff,0xaf]
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@------------------------------------------------------------------------------
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@ unconditional branches without width suffix encode depending of offset size
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@------------------------------------------------------------------------------
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bne #-256
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bgt #254
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bne #-258
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bgt #256
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bne #-1048576
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bgt #1048574
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@ CHECK: bne #-256 @ encoding: [0x80,0xd1]
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@ CHECK: bgt #254 @ encoding: [0x7f,0xdc]
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@ CHECK: bne.w #-258 @ encoding: [0x7f,0xf4,0x7f,0xaf]
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@ CHECK: bgt.w #256 @ encoding: [0x00,0xf3,0x80,0x80]
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@ CHECK: bne.w #-1048576 @ encoding: [0x40,0xf4,0x00,0x80]
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@ CHECK: bgt.w #1048574 @ encoding: [0x3f,0xf3,0xff,0xaf]
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@------------------------------------------------------------------------------
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@ same branch insturction encoding to conditional or unconditional depending
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@ on whether it is in an IT block or not
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@------------------------------------------------------------------------------
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it eq
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addeq r0, r1
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bne #128
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@ CHECK: it eq @ encoding: [0x08,0xbf]
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@ CHECK: addeq r0, r1 @ encoding: [0x08,0x44]
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@ CHECK: bne #128 @ encoding: [0x40,0xd1]
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ite eq
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addeq r0, r1
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bne #128
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@ CHECK: ite eq @ encoding: [0x0c,0xbf]
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@ CHECK: addeq r0, r1 @ encoding: [0x08,0x44]
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@ CHECK: bne #128 @ encoding: [0x40,0xe0]
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