From 5037a1591070247af4f83316ec479829846cc734 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 22 Jan 2005 00:49:16 +0000 Subject: [PATCH] Implicitly defined registers can clobber callee saved registers too! This fixes the return-address-not-being-saved problem in the Alpha backend. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19741 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/PrologEpilogInserter.cpp | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp index 5c4dcdd0617..6d6706d9e88 100644 --- a/lib/CodeGen/PrologEpilogInserter.cpp +++ b/lib/CodeGen/PrologEpilogInserter.cpp @@ -96,6 +96,7 @@ FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); } void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) { const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo(); const TargetFrameInfo *TFI = Fn.getTarget().getFrameInfo(); + const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo(); // Get the callee saved register list... const unsigned *CSRegs = RegInfo->getCalleeSaveRegs(); @@ -133,6 +134,11 @@ void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) { "Register allocation must be performed!"); ModifiedRegs[MO.getReg()] = true; // Register is modified } + + // Mark any implicitly defined registers as being modified. + for (const unsigned *ImpDefs = TII.getImplicitDefs(I->getOpcode()); + *ImpDefs; ++ImpDefs) + ModifiedRegs[*ImpDefs] = true; } ++I; } -- 2.34.1