- Re-enable population count loop idiom recognization

- fix a bug which cause sigfault.
- add two testing cases which was causing crash


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169687 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 126 insertions, 0 deletions

diff --git a/test/Transforms/LoopIdiom/X86/lit.local.cfg b/test/Transforms/LoopIdiom/X86/lit.local.cfg
new file mode 100644
index 0000000000..a8ad0f1a28
--- /dev/null
+++ b/test/Transforms/LoopIdiom/X86/lit.local.cfg
@@ -0,0 +1,6 @@
+config.suffixes = ['.ll', '.c', '.cpp']
+
+targets = set(config.root.targets_to_build.split())
+if not 'X86' in targets:
+    config.unsupported = True
+
diff --git a/test/Transforms/LoopIdiom/X86/popcnt.ll b/test/Transforms/LoopIdiom/X86/popcnt.ll
new file mode 100644
index 0000000000..2f458fb2f1
--- /dev/null
+++ b/test/Transforms/LoopIdiom/X86/popcnt.ll
@@ -0,0 +1,120 @@
+; RUN: opt -loop-idiom < %s -mtriple=x86_64-apple-darwin -mcpu=corei7 -S | FileCheck %s
+
+;To recognize this pattern:
+;int popcount(unsigned long long a) {
+;    int c = 0;
+;    while (a) {
+;        c++;
+;        a &= a - 1;
+;    }
+;    return c;
+;}
+; 
+; CHECK: entry
+; CHECK: llvm.ctpop.i64
+; CHECK: ret
+define i32 @popcount(i64 %a) nounwind uwtable readnone ssp {
+entry:
+  %tobool3 = icmp eq i64 %a, 0
+  br i1 %tobool3, label %while.end, label %while.body
+
+while.body:                                       ; preds = %entry, %while.body
+  %c.05 = phi i32 [ %inc, %while.body ], [ 0, %entry ]
+  %a.addr.04 = phi i64 [ %and, %while.body ], [ %a, %entry ]
+  %inc = add nsw i32 %c.05, 1
+  %sub = add i64 %a.addr.04, -1
+  %and = and i64 %sub, %a.addr.04
+  %tobool = icmp eq i64 %and, 0
+  br i1 %tobool, label %while.end, label %while.body
+
+while.end:                                        ; preds = %while.body, %entry
+  %c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
+  ret i32 %c.0.lcssa
+}
+
+; To recognize this pattern:
+;int popcount(unsigned long long a, int mydata1, int mydata2) {
+;    int c = 0;
+;    while (a) {
+;        c++;
+;        a &= a - 1;
+;        mydata1 *= c;
+;        mydata2 *= (int)a;
+;    }
+;    return c + mydata1 + mydata2;
+;}
+; CHECK: entry
+; CHECK: llvm.ctpop.i64
+; CHECK: ret
+define i32 @popcount2(i64 %a, i32 %mydata1, i32 %mydata2) nounwind uwtable readnone ssp {
+entry:
+  %tobool9 = icmp eq i64 %a, 0
+  br i1 %tobool9, label %while.end, label %while.body
+
+while.body:                                       ; preds = %entry, %while.body
+  %c.013 = phi i32 [ %inc, %while.body ], [ 0, %entry ]
+  %mydata2.addr.012 = phi i32 [ %mul1, %while.body ], [ %mydata2, %entry ]
+  %mydata1.addr.011 = phi i32 [ %mul, %while.body ], [ %mydata1, %entry ]
+  %a.addr.010 = phi i64 [ %and, %while.body ], [ %a, %entry ]
+  %inc = add nsw i32 %c.013, 1
+  %sub = add i64 %a.addr.010, -1
+  %and = and i64 %sub, %a.addr.010
+  %mul = mul nsw i32 %inc, %mydata1.addr.011
+  %conv = trunc i64 %and to i32
+  %mul1 = mul nsw i32 %conv, %mydata2.addr.012
+  %tobool = icmp eq i64 %and, 0
+  br i1 %tobool, label %while.end, label %while.body
+
+while.end:                                        ; preds = %while.body, %entry
+  %c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
+  %mydata2.addr.0.lcssa = phi i32 [ %mydata2, %entry ], [ %mul1, %while.body ]
+  %mydata1.addr.0.lcssa = phi i32 [ %mydata1, %entry ], [ %mul, %while.body ]
+  %add = add i32 %mydata2.addr.0.lcssa, %mydata1.addr.0.lcssa
+  %add2 = add i32 %add, %c.0.lcssa
+  ret i32 %add2
+}
+
+; Some variants once cause crash
+target triple = "x86_64-apple-macosx10.8.0"
+
+define i32 @PopCntCrash1(i64 %a) nounwind uwtable readnone ssp {
+entry:
+  %tobool3 = icmp eq i64 %a, 0
+  br i1 %tobool3, label %while.end, label %while.body
+
+while.body:                                       ; preds = %entry, %while.body
+  %c.05 = phi i32 [ %inc, %while.body ], [ 0, %entry ]
+  %a.addr.04 = phi i64 [ %and, %while.body ], [ %a, %entry ]
+  %t = add i32 %c.05, %c.05
+  %inc = add nsw i32 %t, 1
+  %sub = add i64 %a.addr.04, -1
+  %and = and i64 %sub, %a.addr.04
+  %tobool = icmp eq i64 %and, 0
+  br i1 %tobool, label %while.end, label %while.body
+
+while.end:                                        ; preds = %while.body, %entry
+  %c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
+  ret i32 %c.0.lcssa
+
+; CHECK: entry
+; CHECK: ret 
+}
+
+define i32 @PopCntCrash2(i64 %a, i32 %b) nounwind uwtable readnone ssp {
+entry:
+  %tobool3 = icmp eq i64 %a, 0
+  br i1 %tobool3, label %while.end, label %while.body
+
+while.body:                                       ; preds = %entry, %while.body
+  %c.05 = phi i32 [ %inc, %while.body ], [ %b, %entry ]
+  %a.addr.04 = phi i64 [ %and, %while.body ], [ %a, %entry ]
+  %inc = add nsw i32 %c.05, 1
+  %sub = add i64 %a.addr.04, -1
+  %and = and i64 %sub, %a.addr.04
+  %tobool = icmp eq i64 %and, 0
+  br i1 %tobool, label %while.end, label %while.body
+
+while.end:                                        ; preds = %while.body, %entry
+  %c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
+  ret i32 %c.0.lcssa
+}