1 ; RUN: opt < %s -instcombine -S | grep "call.*stackrestore" | count 1 2 3 declare i8* @llvm.stacksave() 4 declare void @llvm.stackrestore(i8*) 5 6 ;; Test that llvm.stackrestore is removed when possible. 7 define i32* @test1(i32 %P) { 8 %tmp = call i8* @llvm.stacksave( ) 9 call void @llvm.stackrestore( i8* %tmp ) ;; not restoring anything 10 %A = alloca i32, i32 %P 11 ret i32* %A 12 } 13 14 define void @test2(i8* %X) { 15 call void @llvm.stackrestore( i8* %X ) ;; no allocas before return. 16 ret void 17 } 18 19 define void @foo(i32 %size) nounwind { 20 entry: 21 %tmp118124 = icmp sgt i32 %size, 0 ; <i1> [#uses=1] 22 br i1 %tmp118124, label %bb.preheader, label %return 23 24 bb.preheader: ; preds = %entry 25 %tmp25 = add i32 %size, -1 ; <i32> [#uses=1] 26 %tmp125 = icmp slt i32 %size, 1 ; <i1> [#uses=1] 27 %smax = select i1 %tmp125, i32 1, i32 %size ; <i32> [#uses=1] 28 br label %bb 29 30 bb: ; preds = %bb, %bb.preheader 31 %i.0.reg2mem.0 = phi i32 [ 0, %bb.preheader ], [ %indvar.next, %bb ] ; <i32> [#uses=2] 32 %tmp = call i8* @llvm.stacksave( ) ; <i8*> [#uses=1] 33 %tmp23 = alloca i8, i32 %size ; <i8*> [#uses=2] 34 %tmp27 = getelementptr i8* %tmp23, i32 %tmp25 ; <i8*> [#uses=1] 35 store i8 0, i8* %tmp27, align 1 36 %tmp28 = call i8* @llvm.stacksave( ) ; <i8*> [#uses=1] 37 %tmp52 = alloca i8, i32 %size ; <i8*> [#uses=1] 38 %tmp53 = call i8* @llvm.stacksave( ) ; <i8*> [#uses=1] 39 %tmp77 = alloca i8, i32 %size ; <i8*> [#uses=1] 40 %tmp78 = call i8* @llvm.stacksave( ) ; <i8*> [#uses=1] 41 %tmp102 = alloca i8, i32 %size ; <i8*> [#uses=1] 42 call void @bar( i32 %i.0.reg2mem.0, i8* %tmp23, i8* %tmp52, i8* %tmp77, i8* %tmp102, i32 %size ) nounwind 43 call void @llvm.stackrestore( i8* %tmp78 ) 44 call void @llvm.stackrestore( i8* %tmp53 ) 45 call void @llvm.stackrestore( i8* %tmp28 ) 46 call void @llvm.stackrestore( i8* %tmp ) 47 %indvar.next = add i32 %i.0.reg2mem.0, 1 ; <i32> [#uses=2] 48 %exitcond = icmp eq i32 %indvar.next, %smax ; <i1> [#uses=1] 49 br i1 %exitcond, label %return, label %bb 50 51 return: ; preds = %bb, %entry 52 ret void 53 } 54 55 declare void @bar(i32, i8*, i8*, i8*, i8*, i32) 56 57
