From 160a3bf74d1a2b048f65e2162d038ed96eddde01 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 26 May 2010 21:47:28 +0000 Subject: Add StringRef::compare_numeric and use it to sort TableGen register records. This means that our Registers are now ordered R7, R8, R9, R10, R12, ... Not R1, R10, R11, R12, R2, R3, ... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104745 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/StringRef.cpp | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'lib/Support/StringRef.cpp') diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp index 2b262dcd3f..ca0f518a88 100644 --- a/lib/Support/StringRef.cpp +++ b/lib/Support/StringRef.cpp @@ -23,6 +23,10 @@ static char ascii_tolower(char x) { return x; } +static bool ascii_isdigit(char x) { + return x >= '0' && x <= '9'; +} + /// compare_lower - Compare strings, ignoring case. int StringRef::compare_lower(StringRef RHS) const { for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) { @@ -37,6 +41,30 @@ int StringRef::compare_lower(StringRef RHS) const { return Length < RHS.Length ? -1 : 1; } +/// compare_numeric - Compare strings, handle embedded numbers. +int StringRef::compare_numeric(StringRef RHS) const { + for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) { + if (Data[I] == RHS.Data[I]) + continue; + if (ascii_isdigit(Data[I]) && ascii_isdigit(RHS.Data[I])) { + // The longer sequence of numbers is larger. This doesn't really handle + // prefixed zeros well. + for (size_t J = I+1; J != E+1; ++J) { + bool ld = J < Length && ascii_isdigit(Data[J]); + bool rd = J < RHS.Length && ascii_isdigit(RHS.Data[J]); + if (ld != rd) + return rd ? -1 : 1; + if (!rd) + break; + } + } + return Data[I] < RHS.Data[I] ? -1 : 1; + } + if (Length == RHS.Length) + return 0; + return Length < RHS.Length ? -1 : 1; +} + // Compute the edit distance between the two given strings. unsigned StringRef::edit_distance(llvm::StringRef Other, bool AllowReplacements) { -- cgit v1.2.3