Add testcase to make sure we don't generate too many jumps for a une compare.

<rdar://problem/7859988>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191040 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/X86/fp-une-cmp.ll

@@ -0,0 +1,43 @@
+; RUN: llc < %s -march=x86 -mattr=sse4.1 | FileCheck %s
+; <rdar://problem/7859988>
+
+; Make sure we don't generate more jumps than we need to. We used to generate
+; something like this:
+;
+;       jne  LBB0_1
+;       jnp  LBB0_2
+;   LBB0_1:
+;       jmp  LBB0_3
+;   LBB0_2:
+;       addsd ...
+;   LBB0_3:
+;
+; Now we generate this:
+;
+;       jne  LBB0_2
+;       jp   LBB0_2
+;       addsd ...
+;   LBB0_2:
+
+; CHECK:       func
+; CHECK:       jne [[LABEL:.*]]
+; CHECK-NEXT:  jp  [[LABEL]]
+; CHECK-NOT:   jmp
+
+define float @func(float %x, float %y) nounwind readnone optsize ssp {
+entry:
+  %0 = fpext float %x to double
+  %1 = fpext float %y to double
+  %2 = fmul double %0, %1
+  %3 = fcmp une double %2, 0.000000e+00
+  br i1 %3, label %bb2, label %bb1
+
+bb1:
+  %4 = fadd double %2, -1.000000e+00
+  br label %bb2
+
+bb2:
+  %.0.in = phi double [ %4, %bb1 ], [ %2, %entry ]
+  %.0 = fptrunc double %.0.in to float
+  ret float %.0
+}