ARM: fix VEXT encoding corner case

The disassembly of VEXT instructions was too lax in the bits checked. This
fixes the case where the instruction affects Q-registers but a misaligned lane
was specified (should be UNDEFINED).

Patch by Amaury de la Vieuville

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183003 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Tim Northover 2013-05-31 13:47:25 +00:00
parent b6606e46ab
commit e93c701cac
2 changed files with 11 additions and 5 deletions

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@ -5509,8 +5509,9 @@ class VEXTd<string OpcodeStr, string Dt, ValueType Ty, Operand immTy>
IIC_VEXTD, OpcodeStr, Dt, "$Vd, $Vn, $Vm, $index", "",
[(set DPR:$Vd, (Ty (NEONvext (Ty DPR:$Vn),
(Ty DPR:$Vm), imm:$index)))]> {
bits<4> index;
let Inst{11-8} = index{3-0};
bits<3> index;
let Inst{11} = 0b0;
let Inst{10-8} = index{2-0};
}
class VEXTq<string OpcodeStr, string Dt, ValueType Ty, Operand immTy>
@ -5525,14 +5526,14 @@ class VEXTq<string OpcodeStr, string Dt, ValueType Ty, Operand immTy>
}
def VEXTd8 : VEXTd<"vext", "8", v8i8, imm0_7> {
let Inst{11-8} = index{3-0};
let Inst{10-8} = index{2-0};
}
def VEXTd16 : VEXTd<"vext", "16", v4i16, imm0_3> {
let Inst{11-9} = index{2-0};
let Inst{10-9} = index{1-0};
let Inst{8} = 0b0;
}
def VEXTd32 : VEXTd<"vext", "32", v2i32, imm0_1> {
let Inst{11-10} = index{1-0};
let Inst{10} = index{0};
let Inst{9-8} = 0b00;
}
def : Pat<(v2f32 (NEONvext (v2f32 DPR:$Vn),

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@ -0,0 +1,5 @@
# RUN: llvm-mc --disassemble %s -triple=armv7 2>&1 | grep "invalid instruction encoding"
# invalid imm4 value (0b1xxx)
# A8.8.316: if Q == '0' && imm4<3> == '1' then UNDEFINED;
0x8f 0xf9 0xf7 0xf2