From 7ee74a663a3b4d4ee6b55d23362f347ed1d390c2 Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Thu, 21 Mar 2013 21:37:52 +0000 Subject: Implement builtin_{setjmp/longjmp} on PPC This implements SJLJ lowering on PPC, making the Clang functions __builtin_{setjmp/longjmp} functional on PPC platforms. The implementation strategy is similar to that on X86, with the exception that a branch-and-link variant is used to get the right jump address. Credit goes to Bill Schmidt for suggesting the use of the unconditional bcl form (instead of the regular bl instruction) to limit return-address-cache pollution. Benchmarking the speed at -O3 of: static jmp_buf env_sigill; void foo() { __builtin_longjmp(env_sigill,1); } main() { ... for (int i = 0; i < c; ++i) { if (__builtin_setjmp(env_sigill)) { goto done; } else { foo(); } done:; } ... } vs. the same code using the libc setjmp/longjmp functions on a P7 shows that this builtin implementation is ~4x faster with Altivec enabled and ~7.25x faster with Altivec disabled. This comparison is somewhat unfair because the libc version must also save/restore the VSX registers which we don't yet support. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177666 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/PPCRegisterInfo.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'lib/Target/PowerPC/PPCRegisterInfo.cpp') diff --git a/lib/Target/PowerPC/PPCRegisterInfo.cpp b/lib/Target/PowerPC/PPCRegisterInfo.cpp index f3ac23184f..150e241161 100644 --- a/lib/Target/PowerPC/PPCRegisterInfo.cpp +++ b/lib/Target/PowerPC/PPCRegisterInfo.cpp @@ -105,6 +105,18 @@ PPCRegisterInfo::getCallPreservedMask(CallingConv::ID CC) const { return Subtarget.isPPC64() ? CSR_SVR464_RegMask : CSR_SVR432_RegMask; } +const uint32_t* +PPCRegisterInfo::getNoPreservedMask() const { + // The naming here is inverted: The CSR_NoRegs_Altivec has the + // Altivec registers masked so that they're not saved and restored around + // instructions with this preserved mask. + + if (!Subtarget.hasAltivec()) + return CSR_NoRegs_Altivec_RegMask; + + return CSR_NoRegs_RegMask; +} + BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const { BitVector Reserved(getNumRegs()); const PPCFrameLowering *PPCFI = -- cgit v1.2.3