Author: djg Date: Mon Sep 17 09:49:27 2007 New Revision: 42026 URL: http://llvm.org/viewvc/llvm-project?rev=42026&view=rev Log: Emit integer x<1 as x<=0, as comparisons with zero (now includeing 64-bit) can use test instead of cmp with an immediate.
Added: llvm/trunk/test/CodeGen/X86/cmp1.ll Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=42026&r1=42025&r2=42026&view=diff ============================================================================== --- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original) +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Sep 17 09:49:27 2007 @@ -1546,6 +1546,11 @@ // X < 0 -> X == 0, jump on sign. X86CC = X86::COND_S; return true; + } else if (SetCCOpcode == ISD::SETLT && RHSC->getValue() == 1) { + // X < 1 -> X <= 0 + RHS = DAG.getConstant(0, RHS.getValueType()); + X86CC = X86::COND_LE; + return true; } } Added: llvm/trunk/test/CodeGen/X86/cmp1.ll URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/cmp1.ll?rev=42026&view=auto ============================================================================== --- llvm/trunk/test/CodeGen/X86/cmp1.ll (added) +++ llvm/trunk/test/CodeGen/X86/cmp1.ll Mon Sep 17 09:49:27 2007 @@ -0,0 +1,7 @@ +; RUN: llvm-as < %s | llc -march=x86-64 | grep -v cmp + +define i64 @foo(i64 %x) { + %t = icmp slt i64 %x, 1 + %r = zext i1 %t to i64 + ret i64 %r +} _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits