this new test file was accidentally left out of r253573

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253574 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rotateright

test/Transforms/CodeGenPrepare/X86/cttz-ctlz.ll

@@ -0,0 +1,56 @@
+; RUN: opt -S -codegenprepare < %s | FileCheck %s --check-prefix=SLOW
+; RUN: opt -S -codegenprepare -mattr=+bmi < %s | FileCheck %s --check-prefix=FAST_TZ
+; RUN: opt -S -codegenprepare -mattr=+lzcnt < %s | FileCheck %s --check-prefix=FAST_LZ
+
+target triple = "x86_64-unknown-unknown"
+target datalayout = "e-n32:64"
+
+; If the intrinsic is cheap, nothing should change.
+; If the intrinsic is expensive, check if the input is zero to avoid the call. 
+; This is undoing speculation that may have been created by SimplifyCFG + InstCombine.
+
+define i64 @cttz(i64 %A) {
+entry:
+  %z = call i64 @llvm.cttz.i64(i64 %A, i1 false)
+  ret i64 %z
+
+; SLOW-LABEL: @cttz(
+; SLOW: entry:
+; SLOW:   %cmpz = icmp eq i64 %A, 0
+; SLOW:   br i1 %cmpz, label %cond.end, label %cond.false
+; SLOW: cond.false:
+; SLOW:   %z = call i64 @llvm.cttz.i64(i64 %A, i1 true)
+; SLOW:   br label %cond.end
+; SLOW: cond.end:
+; SLOW:   %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ]
+; SLOW:   ret i64 %ctz
+
+; FAST_TZ-LABEL: @cttz(
+; FAST_TZ:  %z = call i64 @llvm.cttz.i64(i64 %A, i1 false)
+; FAST_TZ:  ret i64 %z
+}
+
+define i64 @ctlz(i64 %A) {
+entry:
+  %z = call i64 @llvm.ctlz.i64(i64 %A, i1 false)
+  ret i64 %z
+
+; SLOW-LABEL: @ctlz(
+; SLOW: entry:
+; SLOW:   %cmpz = icmp eq i64 %A, 0
+; SLOW:   br i1 %cmpz, label %cond.end, label %cond.false
+; SLOW: cond.false:
+; SLOW:   %z = call i64 @llvm.ctlz.i64(i64 %A, i1 true)
+; SLOW:   br label %cond.end
+; SLOW: cond.end:
+; SLOW:   %ctz = phi i64 [ 64, %entry ], [ %z, %cond.false ]
+; SLOW:   ret i64 %ctz
+
+; FAST_LZ-LABEL: @ctlz(
+; FAST_LZ:  %z = call i64 @llvm.ctlz.i64(i64 %A, i1 false)
+; FAST_LZ:  ret i64 %z
+}
+
+declare i64 @llvm.cttz.i64(i64, i1)
+declare i64 @llvm.ctlz.i64(i64, i1)
+