From 9637da60835a60f8ccd8289d04c60b2dcd4b9b5a Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Thu, 26 Sep 2013 09:18:48 +0000 Subject: PPC: Allow partial fills in writeNopData() When asked to pad an irregular number of bytes, we should fill with zeros. This is consistent with the behavior specified in the AIX Assembler Language Reference as well as other LLVM and binutils assemblers. N.B. There is a small deviation from binutils' PPC assembler: when handling pads which are greater than 4 bytes but not mod 4, binutils will not emit any NOP sequences at all and only use zeros. This may or may not be a bug but there is no excellent rationale as to why that behavior is important to emulate. If that behavior is needed, we can change writeNopData() to behave in the same way. This fixes PR17352. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191426 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'lib/Target/PowerPC') diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp index 91f1160..0d42081 100644 --- a/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp +++ b/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp @@ -132,14 +132,17 @@ public: } bool writeNopData(uint64_t Count, MCObjectWriter *OW) const { - // Can't emit NOP with size not multiple of 32-bits - if (Count % 4 != 0) - return false; - uint64_t NumNops = Count / 4; for (uint64_t i = 0; i != NumNops; ++i) OW->Write32(0x60000000); + switch (Count % 4) { + default: break; // No leftover bytes to write + case 1: OW->Write8(0); break; + case 2: OW->Write16(0); break; + case 3: OW->Write16(0); OW->Write8(0); break; + } + return true; } -- cgit v1.1