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AArch64: treat MC expressions as 2s complement arithmetic.
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We had a couple of over-zealous diagnostics that meant IR with a reasonable and
valid interpretation was rejected.
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TNorthover committed Oct 8, 2020
1 parent 7d01bb8 commit 38348fa
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Showing 2 changed files with 9 additions and 16 deletions.
16 changes: 0 additions & 16 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -154,19 +154,6 @@ static unsigned AdrImmBits(unsigned Value) {
return (hi19 << 5) | (lo2 << 29);
}

static bool valueFitsIntoFixupKind(unsigned Kind, uint64_t Value) {
unsigned NumBits;
switch(Kind) {
case FK_Data_1: NumBits = 8; break;
case FK_Data_2: NumBits = 16; break;
case FK_Data_4: NumBits = 32; break;
case FK_Data_8: NumBits = 64; break;
default: return true;
}
return isUIntN(NumBits, Value) ||
isIntN(NumBits, static_cast<int64_t>(Value));
}

static uint64_t adjustFixupValue(const MCFixup &Fixup, const MCValue &Target,
uint64_t Value, MCContext &Ctx,
const Triple &TheTriple, bool IsResolved) {
Expand Down Expand Up @@ -341,9 +328,6 @@ static uint64_t adjustFixupValue(const MCFixup &Fixup, const MCValue &Target,
case FK_Data_2:
case FK_Data_4:
case FK_Data_8:
if (!valueFitsIntoFixupKind(Fixup.getTargetKind(), Value))
Ctx.reportError(Fixup.getLoc(), "fixup value too large for data type!");
LLVM_FALLTHROUGH;
case FK_SecRel_2:
case FK_SecRel_4:
return Value;
Expand Down
9 changes: 9 additions & 0 deletions llvm/test/CodeGen/AArch64/2s-complement-asm.ll
Original file line number Diff line number Diff line change
@@ -0,0 +1,9 @@
; RUN: llc -mtriple=arm64-apple-ios %s -filetype=obj -o - | llvm-objdump --macho --section __DATA,__data - | FileCheck %s

; CHECK: Contents of (__DATA,__data) section
; CHECK: 0000002a 59ed145d
@other = global i32 42
@var = global i32 sub(i32 646102975,
i32 add (i32 trunc(i64 sub(i64 ptrtoint(i32* @var to i64),
i64 ptrtoint(i32* @other to i64)) to i32),
i32 3432360802))

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