1 files changed, 83 insertions, 0 deletions
diff --git a/test/CodeGen/X86/narrow-shl-load.ll b/test/CodeGen/X86/narrow-shl-load.ll
new file mode 100644
index 000000000000..ef27cbc3418c
--- /dev/null
+++ b/test/CodeGen/X86/narrow-shl-load.ll
@@ -0,0 +1,83 @@
+; RUN: llc -march=x86-64 < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-pc-linux-gnu"
+
+; DAGCombiner should fold this code in finite time.
+; rdar://8606584
+
+define void @test1() nounwind readnone {
+bb.nph:
+  br label %while.cond
+
+while.cond:                                       ; preds = %while.cond, %bb.nph
+  %tmp6 = load i32* undef, align 4
+  %and = or i64 undef, undef
+  %conv11 = zext i32 undef to i64
+  %conv14 = zext i32 %tmp6 to i64
+  %shl15 = shl i64 %conv14, 1
+  %shl15.masked = and i64 %shl15, 4294967294
+  %and17 = or i64 %shl15.masked, %conv11
+  %add = add i64 %and17, 1
+  %xor = xor i64 %add, %and
+  %tmp20 = load i64* undef, align 8
+  %add21 = add i64 %xor, %tmp20
+  %conv22 = trunc i64 %add21 to i32
+  store i32 %conv22, i32* undef, align 4
+  br i1 false, label %while.end, label %while.cond
+
+while.end:                                        ; preds = %while.cond
+  ret void
+}
+
+
+; DAGCombiner shouldn't fold the sdiv (ashr) away.
+; rdar://8636812
+; CHECK: test2:
+; CHECK:   sarl
+
+define i32 @test2() nounwind {
+entry:
+  %i = alloca i32, align 4
+  %j = alloca i8, align 1
+  store i32 127, i32* %i, align 4
+  store i8 0, i8* %j, align 1
+  %tmp3 = load i32* %i, align 4
+  %mul = mul nsw i32 %tmp3, 2
+  %conv4 = trunc i32 %mul to i8
+  %conv5 = sext i8 %conv4 to i32
+  %div6 = sdiv i32 %conv5, 2
+  %conv7 = trunc i32 %div6 to i8
+  %conv9 = sext i8 %conv7 to i32
+  %cmp = icmp eq i32 %conv9, -1
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  ret i32 0
+
+if.end:                                           ; preds = %entry
+  call void @abort() noreturn
+  unreachable
+}
+
+declare void @abort() noreturn
+
+declare void @exit(i32) noreturn
+
+; DAG Combiner can't fold this into a load of the 1'th byte.
+; PR8757
+define i32 @test3(i32 *%P) nounwind ssp {
+  volatile store i32 128, i32* %P
+  %tmp4.pre = load i32* %P
+  %phitmp = trunc i32 %tmp4.pre to i16
+  %phitmp13 = shl i16 %phitmp, 8
+  %phitmp14 = ashr i16 %phitmp13, 8
+  %phitmp15 = lshr i16 %phitmp14, 8
+  %phitmp16 = zext i16 %phitmp15 to i32
+  ret i32 %phitmp16
+  
+; CHECK: movl	$128, (%rdi)
+; CHECK-NEXT: movsbl	(%rdi), %eax
+; CHECK-NEXT: movzbl	%ah, %eax
+; CHECK-NEXT: ret
+}