From 6ac95f967930ad9bad38363f8b79efb67bc1d58c Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 6 Jan 2005 21:19:16 +0000 Subject: [PATCH] Codegen -1 and -0.0 more efficiently. This implements CodeGen/X86/negatize_zero.ll git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19313 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86ISelSimple.cpp | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/Target/X86/X86ISelSimple.cpp b/lib/Target/X86/X86ISelSimple.cpp index 5e6fd2fbd2d..4aeab3e5184 100644 --- a/lib/Target/X86/X86ISelSimple.cpp +++ b/lib/Target/X86/X86ISelSimple.cpp @@ -560,8 +560,15 @@ void X86ISel::copyConstantToRegister(MachineBasicBlock *MBB, BuildMI(*MBB, IP, X86::FLD0, 0, R); else if (CFP->isExactlyValue(+1.0)) BuildMI(*MBB, IP, X86::FLD1, 0, R); - else { // FIXME: PI, other native values - // FIXME: Could handle -1.0 with FLD1/FCHS + else if (CFP->isExactlyValue(-0.0)) { + unsigned Tmp = makeAnotherReg(Type::DoubleTy); + BuildMI(*MBB, IP, X86::FLD0, 0, Tmp); + BuildMI(*MBB, IP, X86::FCHS, 1, R).addReg(Tmp); + } else if (CFP->isExactlyValue(-1.0)) { + unsigned Tmp = makeAnotherReg(Type::DoubleTy); + BuildMI(*MBB, IP, X86::FLD1, 0, Tmp); + BuildMI(*MBB, IP, X86::FCHS, 1, R).addReg(Tmp); + } else { // FIXME: PI, other native values // FIXME: 2*PI -> LDPI + FADD // Otherwise we need to spill the constant to memory. -- 2.34.1