; RUN: opt < %s -functionattrs -S | FileCheck %s @g = global i32* null ; [#uses=1] ; CHECK: define i32* @c1(i32* readnone %q) define i32* @c1(i32* %q) { ret i32* %q } ; CHECK: define void @c2(i32* %q) ; It would also be acceptable to mark %q as readnone. Update @c3 too. define void @c2(i32* %q) { store i32* %q, i32** @g ret void } ; CHECK: define void @c3(i32* %q) define void @c3(i32* %q) { call void @c2(i32* %q) ret void } ; CHECK: define i1 @c4(i32* %q, i32 %bitno) define i1 @c4(i32* %q, i32 %bitno) { %tmp = ptrtoint i32* %q to i32 %tmp2 = lshr i32 %tmp, %bitno %bit = trunc i32 %tmp2 to i1 br i1 %bit, label %l1, label %l0 l0: ret i1 0 ; escaping value not caught by def-use chaining. l1: ret i1 1 ; escaping value not caught by def-use chaining. } @lookup_table = global [2 x i1] [ i1 0, i1 1 ] ; CHECK: define i1 @c5(i32* %q, i32 %bitno) define i1 @c5(i32* %q, i32 %bitno) { %tmp = ptrtoint i32* %q to i32 %tmp2 = lshr i32 %tmp, %bitno %bit = and i32 %tmp2, 1 ; subtle escape mechanism follows %lookup = getelementptr [2 x i1], [2 x i1]* @lookup_table, i32 0, i32 %bit %val = load i1, i1* %lookup ret i1 %val } declare void @throw_if_bit_set(i8*, i8) readonly ; CHECK: define i1 @c6(i8* readonly %q, i8 %bit) define i1 @c6(i8* %q, i8 %bit) { invoke void @throw_if_bit_set(i8* %q, i8 %bit) to label %ret0 unwind label %ret1 ret0: ret i1 0 ret1: %exn = landingpad {i8*, i32} personality i32 (...)* @__gxx_personality_v0 cleanup ret i1 1 } declare i32 @__gxx_personality_v0(...) define i1* @lookup_bit(i32* %q, i32 %bitno) readnone nounwind { %tmp = ptrtoint i32* %q to i32 %tmp2 = lshr i32 %tmp, %bitno %bit = and i32 %tmp2, 1 %lookup = getelementptr [2 x i1], [2 x i1]* @lookup_table, i32 0, i32 %bit ret i1* %lookup } ; CHECK: define i1 @c7(i32* readonly %q, i32 %bitno) define i1 @c7(i32* %q, i32 %bitno) { %ptr = call i1* @lookup_bit(i32* %q, i32 %bitno) %val = load i1, i1* %ptr ret i1 %val } ; CHECK: define i32 @nc1(i32* %q, i32* nocapture %p, i1 %b) define i32 @nc1(i32* %q, i32* %p, i1 %b) { e: br label %l l: %x = phi i32* [ %p, %e ] %y = phi i32* [ %q, %e ] %tmp = bitcast i32* %x to i32* ; [#uses=2] %tmp2 = select i1 %b, i32* %tmp, i32* %y %val = load i32, i32* %tmp2 ; [#uses=1] store i32 0, i32* %tmp store i32* %y, i32** @g ret i32 %val } ; CHECK: define i32 @nc1_addrspace(i32* %q, i32 addrspace(1)* nocapture %p, i1 %b) define i32 @nc1_addrspace(i32* %q, i32 addrspace(1)* %p, i1 %b) { e: br label %l l: %x = phi i32 addrspace(1)* [ %p, %e ] %y = phi i32* [ %q, %e ] %tmp = addrspacecast i32 addrspace(1)* %x to i32* ; [#uses=2] %tmp2 = select i1 %b, i32* %tmp, i32* %y %val = load i32, i32* %tmp2 ; [#uses=1] store i32 0, i32* %tmp store i32* %y, i32** @g ret i32 %val } ; CHECK: define void @nc2(i32* nocapture %p, i32* %q) define void @nc2(i32* %p, i32* %q) { %1 = call i32 @nc1(i32* %q, i32* %p, i1 0) ; [#uses=0] ret void } ; CHECK: define void @nc3(void ()* nocapture %p) define void @nc3(void ()* %p) { call void %p() ret void } declare void @external(i8*) readonly nounwind ; CHECK: define void @nc4(i8* nocapture readonly %p) define void @nc4(i8* %p) { call void @external(i8* %p) ret void } ; CHECK: define void @nc5(void (i8*)* nocapture %f, i8* nocapture %p) define void @nc5(void (i8*)* %f, i8* %p) { call void %f(i8* %p) readonly nounwind call void %f(i8* nocapture %p) ret void } ; CHECK: define void @test1_1(i8* nocapture readnone %x1_1, i8* %y1_1) ; It would be acceptable to add readnone to %y1_1 and %y1_2. define void @test1_1(i8* %x1_1, i8* %y1_1) { call i8* @test1_2(i8* %x1_1, i8* %y1_1) store i32* null, i32** @g ret void } ; CHECK: define i8* @test1_2(i8* nocapture readnone %x1_2, i8* %y1_2) define i8* @test1_2(i8* %x1_2, i8* %y1_2) { call void @test1_1(i8* %x1_2, i8* %y1_2) store i32* null, i32** @g ret i8* %y1_2 } ; CHECK: define void @test2(i8* nocapture readnone %x2) define void @test2(i8* %x2) { call void @test2(i8* %x2) store i32* null, i32** @g ret void } ; CHECK: define void @test3(i8* nocapture readnone %x3, i8* nocapture readnone %y3, i8* nocapture readnone %z3) define void @test3(i8* %x3, i8* %y3, i8* %z3) { call void @test3(i8* %z3, i8* %y3, i8* %x3) store i32* null, i32** @g ret void } ; CHECK: define void @test4_1(i8* %x4_1) define void @test4_1(i8* %x4_1) { call i8* @test4_2(i8* %x4_1, i8* %x4_1, i8* %x4_1) store i32* null, i32** @g ret void } ; CHECK: define i8* @test4_2(i8* nocapture readnone %x4_2, i8* readnone %y4_2, i8* nocapture readnone %z4_2) define i8* @test4_2(i8* %x4_2, i8* %y4_2, i8* %z4_2) { call void @test4_1(i8* null) store i32* null, i32** @g ret i8* %y4_2 } declare i8* @test5_1(i8* %x5_1) ; CHECK: define void @test5_2(i8* %x5_2) define void @test5_2(i8* %x5_2) { call i8* @test5_1(i8* %x5_2) store i32* null, i32** @g ret void } declare void @test6_1(i8* %x6_1, i8* nocapture %y6_1, ...) ; CHECK: define void @test6_2(i8* %x6_2, i8* nocapture %y6_2, i8* %z6_2) define void @test6_2(i8* %x6_2, i8* %y6_2, i8* %z6_2) { call void (i8*, i8*, ...) @test6_1(i8* %x6_2, i8* %y6_2, i8* %z6_2) store i32* null, i32** @g ret void }