-; RUN: llc < %s -march=x86 | grep movsbl
+; RUN: llc < %s -march=x86 | FileCheck %s
-define i32 @foo(i32 %X) nounwind {
+; When doing sign extension, use the sext-load lowering to take advantage of
+; x86's sign extension during loads.
+;
+; CHECK-LABEL: test1:
+; CHECK: movsbl {{.*}}, %eax
+; CHECK-NEXT: ret
+define i32 @test1(i32 %X) nounwind {
entry:
%tmp12 = trunc i32 %X to i8 ; <i8> [#uses=1]
%tmp123 = sext i8 %tmp12 to i32 ; <i32> [#uses=1]
ret i32 %tmp123
}
+; When using a sextload representation, ensure that the sign extension is
+; preserved even when removing shifted-out low bits.
+;
+; CHECK-LABEL: test2:
+; CHECK: movswl {{.*}}, %eax
+; CHECK-NEXT: ret
+define i32 @test2({i16, [6 x i8]}* %this) {
+entry:
+ %b48 = getelementptr inbounds { i16, [6 x i8] }* %this, i32 0, i32 1
+ %cast = bitcast [6 x i8]* %b48 to i48*
+ %bf.load = load i48* %cast, align 2
+ %bf.ashr = ashr i48 %bf.load, 32
+ %bf.cast = trunc i48 %bf.ashr to i32
+ ret i32 %bf.cast
+}