Recommit the fix for rdar://9289512 with a couple tweaks to

fix bugs exposed by the gcc dejagnu testsuite:
1. The load may actually be used by a dead instruction, which
   would cause an assert.
2. The load may not be used by the current chain of instructions,
   and we could move it past a side-effecting instruction. Change
   how we process uses to define the problem away.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130018 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/test/CodeGen/X86/fast-isel-x86-64.ll b/test/CodeGen/X86/fast-isel-x86-64.ll
index 5762ef3312..d45a54fb14 100644
--- a/test/CodeGen/X86/fast-isel-x86-64.ll
+++ b/test/CodeGen/X86/fast-isel-x86-64.ll
@@ -14,6 +14,28 @@ define i32 @test1(i32 %i) nounwind ssp {
 ; CHECK: andl	$8, 
 
 
+; rdar://9289512 - The load should fold into the compare.
+define void @test2(i64 %x) nounwind ssp {
+entry:
+  %x.addr = alloca i64, align 8
+  store i64 %x, i64* %x.addr, align 8
+  %tmp = load i64* %x.addr, align 8
+  %cmp = icmp sgt i64 %tmp, 42
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  ret void
+; CHECK: test2:
+; CHECK: movq	%rdi, -8(%rsp)
+; CHECK: cmpq	$42, -8(%rsp)
+}
+
+
+
+
 @G = external global i32
 define i64 @test3() nounwind {
   %A = ptrtoint i32* @G to i64
@@ -178,3 +200,28 @@ block2:
   call void (...)* @test16callee(double 1.000000e+00)
   ret void
 }
+
+
+declare void @foo() unnamed_addr ssp align 2
+
+; Verify that we don't fold the load into the compare here.  That would move it
+; w.r.t. the call.
+define i32 @test17(i32 *%P) ssp nounwind {
+entry:
+  %tmp = load i32* %P
+  %cmp = icmp ne i32 %tmp, 5
+  call void @foo()
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  ret i32 1
+
+if.else:                                          ; preds = %entry
+  ret i32 2
+; CHECK: test17:
+; CHECK: movl	(%rdi), %eax
+; CHECK: callq _foo
+; CHECK: cmpl	$5, %eax
+; CHECK-NEXT: je 
+}
+