diff options
| -rw-r--r-- | llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/MC/ARM/thumb-cb-negative-offsets.s | 14 |
2 files changed, 17 insertions, 3 deletions
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp index 5ac2d65a89e..2c3214fe20e 100644 --- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp +++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp @@ -578,8 +578,10 @@ unsigned ARMAsmBackend::adjustFixupValue(const MCFixup &Fixup, uint64_t Value, // Offset by 4, and don't encode the low two bits. return ((Value - 4) >> 2) & 0xff; case ARM::fixup_arm_thumb_cb: { - // CB instructions can only branch to offsets in [0, 126] in multiples of 2 - if (Ctx && ((int64_t)Value < 0 || Value > 0x3e || Value & 1)) { + // CB instructions can only branch to offsets in [4, 126] in multiples of 2 + // so ensure that the raw value LSB is zero and it lies in [2, 130]. + // An offset of 2 will be relaxed to a NOP. + if (Ctx && ((int64_t)Value < 2 || Value > 0x82 || Value & 1)) { Ctx->reportError(Fixup.getLoc(), "out of range pc-relative fixup value"); return 0; } diff --git a/llvm/test/MC/ARM/thumb-cb-negative-offsets.s b/llvm/test/MC/ARM/thumb-cb-negative-offsets.s index cd70126ea95..8abff68de14 100644 --- a/llvm/test/MC/ARM/thumb-cb-negative-offsets.s +++ b/llvm/test/MC/ARM/thumb-cb-negative-offsets.s @@ -16,4 +16,16 @@ label0: .space 1000 label1: - .word 4 + nop + +@ CHECK: out of range pc-relative fixup value + cbz r0, label2 + .space 130 +label2: + nop + +@ CHECK-NOT: label3 + cbnz r0, label3 + .space 128 +label3: + nop |
