1; RUN: opt < %s -passes=instcombine -S | FileCheck %s 2 3@glob = global i32 0 4 5declare ptr @llvm.stacksave() 6declare void @llvm.stackrestore(ptr) 7 8;; Test that llvm.stackrestore is removed when possible. 9define ptr @test1(i32 %P) { 10 %tmp = call ptr @llvm.stacksave( ) 11 call void @llvm.stackrestore( ptr %tmp ) ;; not restoring anything 12 %A = alloca i32, i32 %P 13 ret ptr %A 14} 15 16; CHECK-LABEL: define ptr @test1( 17; CHECK-NOT: call void @llvm.stackrestore 18; CHECK: ret ptr 19 20define void @test2(ptr %X) { 21 call void @llvm.stackrestore( ptr %X ) ;; no allocas before return. 22 ret void 23} 24 25; CHECK-LABEL: define void @test2( 26; CHECK-NOT: call void @llvm.stackrestore 27; CHECK: ret void 28 29define void @foo(i32 %size) nounwind { 30entry: 31 %tmp118124 = icmp sgt i32 %size, 0 ; <i1> [#uses=1] 32 br i1 %tmp118124, label %bb.preheader, label %return 33 34bb.preheader: ; preds = %entry 35 %tmp25 = add i32 %size, -1 ; <i32> [#uses=1] 36 %tmp125 = icmp slt i32 %size, 1 ; <i1> [#uses=1] 37 %smax = select i1 %tmp125, i32 1, i32 %size ; <i32> [#uses=1] 38 br label %bb 39 40bb: ; preds = %bb, %bb.preheader 41 %i.0.reg2mem.0 = phi i32 [ 0, %bb.preheader ], [ %indvar.next, %bb ] ; <i32> [#uses=2] 42 %tmp = call ptr @llvm.stacksave( ) ; <ptr> [#uses=1] 43 %tmp23 = alloca i8, i32 %size ; <ptr> [#uses=2] 44 %tmp27 = getelementptr i8, ptr %tmp23, i32 %tmp25 ; <ptr> [#uses=1] 45 store i8 0, ptr %tmp27, align 1 46 %tmp28 = call ptr @llvm.stacksave( ) ; <ptr> [#uses=1] 47 %tmp52 = alloca i8, i32 %size ; <ptr> [#uses=1] 48 %tmp53 = call ptr @llvm.stacksave( ) ; <ptr> [#uses=1] 49 %tmp77 = alloca i8, i32 %size ; <ptr> [#uses=1] 50 %tmp78 = call ptr @llvm.stacksave( ) ; <ptr> [#uses=1] 51 %tmp102 = alloca i8, i32 %size ; <ptr> [#uses=1] 52 call void @bar( i32 %i.0.reg2mem.0, ptr %tmp23, ptr %tmp52, ptr %tmp77, ptr %tmp102, i32 %size ) nounwind 53 call void @llvm.stackrestore( ptr %tmp78 ) 54 call void @llvm.stackrestore( ptr %tmp53 ) 55 call void @llvm.stackrestore( ptr %tmp28 ) 56 call void @llvm.stackrestore( ptr %tmp ) 57 %indvar.next = add i32 %i.0.reg2mem.0, 1 ; <i32> [#uses=2] 58 %exitcond = icmp eq i32 %indvar.next, %smax ; <i1> [#uses=1] 59 br i1 %exitcond, label %return, label %bb 60 61return: ; preds = %bb, %entry 62 ret void 63} 64 65; CHECK-LABEL: define void @foo( 66; CHECK: %tmp = call ptr @llvm.stacksave.p0() 67; CHECK: alloca i8 68; CHECK-NOT: stacksave 69; CHECK: call void @bar( 70; CHECK-NEXT: call void @llvm.stackrestore.p0(ptr %tmp) 71; CHECK: ret void 72 73declare void @bar(i32, ptr, ptr, ptr, ptr, i32) 74 75declare void @inalloca_callee(ptr inalloca(i32)) 76 77define void @test3(i32 %c) { 78entry: 79 br label %loop 80 81loop: 82 %i = phi i32 [0, %entry], [%i1, %loop] 83 %save1 = call ptr @llvm.stacksave() 84 %argmem = alloca inalloca i32 85 store i32 0, ptr %argmem 86 call void @inalloca_callee(ptr inalloca(i32) %argmem) 87 88 ; This restore cannot be deleted, the restore below does not make it dead. 89 call void @llvm.stackrestore(ptr %save1) 90 91 ; FIXME: We should be able to remove this save/restore pair, but we don't. 92 %save2 = call ptr @llvm.stacksave() 93 store i32 0, ptr @glob 94 call void @llvm.stackrestore(ptr %save2) 95 %i1 = add i32 1, %i 96 %done = icmp eq i32 %i1, %c 97 br i1 %done, label %loop, label %return 98 99return: 100 ret void 101} 102 103; CHECK-LABEL: define void @test3( 104; CHECK: loop: 105; CHECK: %i = phi i32 [ 0, %entry ], [ %i1, %loop ] 106; CHECK: %save1 = call ptr @llvm.stacksave.p0() 107; CHECK: %argmem = alloca inalloca i32 108; CHECK: store i32 0, ptr %argmem 109; CHECK: call void @inalloca_callee(ptr {{.*}} inalloca(i32) %argmem) 110; CHECK: call void @llvm.stackrestore.p0(ptr %save1) 111; CHECK: br i1 %done, label %loop, label %return 112; CHECK: ret void 113 114define i32 @test4(i32 %m, ptr %a, ptr %b) { 115entry: 116 br label %for.body 117 118for.body: 119 %x.012 = phi i32 [ 0, %entry ], [ %add2, %for.body ] 120 %i.011 = phi i32 [ 0, %entry ], [ %inc, %for.body ] 121 %0 = call ptr @llvm.stacksave() 122 %load1 = load i32, ptr %a, align 4 123 %mul1 = mul nsw i32 %load1, %m 124 %add1 = add nsw i32 %mul1, %x.012 125 call void @llvm.stackrestore(ptr %0) 126 %load2 = load i32, ptr %b, align 4 127 %mul2 = mul nsw i32 %load2, %m 128 %add2 = add nsw i32 %mul2, %add1 129 call void @llvm.stackrestore(ptr %0) 130 %inc = add nuw nsw i32 %i.011, 1 131 %exitcond.not = icmp eq i32 %inc, 100 132 br i1 %exitcond.not, label %for.cond.cleanup, label %for.body 133 134for.cond.cleanup: 135 ret i32 %add2 136} 137 138; CHECK-LABEL: define i32 @test4( 139; CHECK-NOT: call void @llvm.stackrestore 140; CHECK: ret i32 %add2 141