1 ; RUN: llc < %s -march=x86 | FileCheck %s 2 3 ; When doing sign extension, use the sext-load lowering to take advantage of 4 ; x86's sign extension during loads. 5 ; 6 ; CHECK-LABEL: test1: 7 ; CHECK: movsbl {{.*}}, %eax 8 ; CHECK-NEXT: ret 9 define i32 @test1(i32 %X) nounwind { 10 entry: 11 %tmp12 = trunc i32 %X to i8 ; <i8> [#uses=1] 12 %tmp123 = sext i8 %tmp12 to i32 ; <i32> [#uses=1] 13 ret i32 %tmp123 14 } 15 16 ; When using a sextload representation, ensure that the sign extension is 17 ; preserved even when removing shifted-out low bits. 18 ; 19 ; CHECK-LABEL: test2: 20 ; CHECK: movswl {{.*}}, %eax 21 ; CHECK-NEXT: ret 22 define i32 @test2({i16, [6 x i8]}* %this) { 23 entry: 24 %b48 = getelementptr inbounds { i16, [6 x i8] }, { i16, [6 x i8] }* %this, i32 0, i32 1 25 %cast = bitcast [6 x i8]* %b48 to i48* 26 %bf.load = load i48, i48* %cast, align 2 27 %bf.ashr = ashr i48 %bf.load, 32 28 %bf.cast = trunc i48 %bf.ashr to i32 29 ret i32 %bf.cast 30 } 31
