diff --git a/lib/Target/R600/SIRegisterInfo.cpp b/lib/Target/R600/SIRegisterInfo.cpp index 6030ce8df46..13a89743677 100644 --- a/lib/Target/R600/SIRegisterInfo.cpp +++ b/lib/Target/R600/SIRegisterInfo.cpp @@ -268,7 +268,22 @@ void SIRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI, .addReg(SubReg); } } - TII->insertNOPs(MI, 3); + + // TODO: only do this when it is needed + switch (MF->getSubtarget().getGeneration()) { + case AMDGPUSubtarget::SOUTHERN_ISLANDS: + // "VALU writes SGPR" -> "SMRD reads that SGPR" needs "S_NOP 3" on SI + TII->insertNOPs(MI, 3); + break; + case AMDGPUSubtarget::SEA_ISLANDS: + break; + default: // VOLCANIC_ISLANDS and later + // "VALU writes SGPR -> VMEM reads that SGPR" needs "S_NOP 4" on VI + // and later. This also applies to VALUs which write VCC, but we're + // unlikely to see VMEM use VCC. + TII->insertNOPs(MI, 4); + } + MI->eraseFromParent(); break; }