Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.

It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables.

This also adds backend support for generating the jump-instruction tables on ARM and X86.
Note that since the jumptable attribute creates a second function pointer for a
function, any function marked with jumptable must also be marked with unnamed_addr.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 351 insertions, 0 deletions

diff --git a/test/CodeGen/X86/jump_table_alias.ll b/test/CodeGen/X86/jump_table_alias.ll
new file mode 100644
index 0000000000..f3691fda22
--- /dev/null
+++ b/test/CodeGen/X86/jump_table_alias.ll
@@ -0,0 +1,33 @@
+; RUN: llc <%s -jump-table-type=single | FileCheck %s
+target triple = "x86_64-unknown-linux-gnu"
+define i32 @f() unnamed_addr jumptable {
+entry:
+  ret i32 0
+}
+
+@i = alias internal i32 ()* @f
+@j = alias i32 ()* @f
+
+define i32 @main(i32 %argc, i8** %argv) {
+  %temp = alloca i32 ()*, align 8
+  store i32 ()* @i, i32()** %temp, align 8
+; CHECK: movq    $__llvm_jump_instr_table_0_1
+  %1 = load i32 ()** %temp, align 8
+; CHECK: movl    $__llvm_jump_instr_table_0_1
+  %2 = call i32 ()* %1()
+  %3 = call i32 ()* @i()
+; CHECK: callq   i
+  %4 = call i32 ()* @j()
+; CHECK: callq   j
+  ret i32 %3
+}
+
+; There should only be one table, even though there are two GlobalAliases,
+; because they both alias the same value.
+
+; CHECK:         .globl  __llvm_jump_instr_table_0_1
+; CHECK:         .align  8, 0x90
+; CHECK:         .type   __llvm_jump_instr_table_0_1,@function
+; CHECK: __llvm_jump_instr_table_0_1:
+; CHECK:         jmp     f@PLT
+
diff --git a/test/CodeGen/X86/jump_table_bitcast.ll b/test/CodeGen/X86/jump_table_bitcast.ll
new file mode 100644
index 0000000000..33a798f7a6
--- /dev/null
+++ b/test/CodeGen/X86/jump_table_bitcast.ll
@@ -0,0 +1,46 @@
+; RUN: llc <%s -jump-table-type=single | FileCheck %s
+target triple = "x86_64-unknown-linux-gnu"
+define i32 @f() unnamed_addr jumptable {
+  ret i32 0
+}
+
+define i32 @g(i8* %a) unnamed_addr jumptable {
+  ret i32 0
+}
+
+define void @h(void ()* %func) unnamed_addr jumptable {
+  ret void
+}
+
+define i32 @main() {
+  %g = alloca i32 (...)*, align 8
+  store i32 (...)* bitcast (i32 ()* @f to i32 (...)*), i32 (...)** %g, align 8
+; CHECK: movq    $__llvm_jump_instr_table_0_[[ENTRY:1|2|3]], (%rsp)
+; CHECK: movl    $__llvm_jump_instr_table_0_[[ENTRY]], %ecx
+  %1 = load i32 (...)** %g, align 8
+  %call = call i32 (...)* %1()
+  call void (void ()*)* @h(void ()* bitcast (void (void ()*)* @h to void ()*))
+; CHECK: movl    $__llvm_jump_instr_table_0_{{1|2|3}}, %edi
+; CHECK: callq   h
+
+  %a = call i32 (i32*)* bitcast (i32 (i8*)* @g to i32(i32*)*)(i32* null)
+; CHECK: callq g
+  ret i32 %a
+}
+
+; CHECK:         .globl  __llvm_jump_instr_table_0_1
+; CHECK:         .align  8, 0x90
+; CHECK:         .type   __llvm_jump_instr_table_0_1,@function
+; CHECK: __llvm_jump_instr_table_0_1:
+; CHECK:         jmp     {{f|g|h}}@PLT
+; CHECK:         .globl  __llvm_jump_instr_table_0_2
+; CHECK:         .align  8, 0x90
+; CHECK:         .type   __llvm_jump_instr_table_0_2,@function
+; CHECK: __llvm_jump_instr_table_0_2:
+; CHECK:         jmp     {{f|g|h}}@PLT
+; CHECK:         .globl  __llvm_jump_instr_table_0_3
+; CHECK:         .align  8, 0x90
+; CHECK:         .type   __llvm_jump_instr_table_0_3,@function
+; CHECK: __llvm_jump_instr_table_0_3:
+; CHECK:         jmp     {{f|g|h}}@PLT
+
diff --git a/test/CodeGen/X86/jump_tables.ll b/test/CodeGen/X86/jump_tables.ll
new file mode 100644
index 0000000000..5a0aed0c17
--- /dev/null
+++ b/test/CodeGen/X86/jump_tables.ll
@@ -0,0 +1,272 @@
+; RUN: llc <%s -jump-table-type=single | FileCheck --check-prefix=SINGLE %s
+; RUN: llc <%s -jump-table-type=arity | FileCheck --check-prefix=ARITY %s
+; RUN: llc <%s -jump-table-type=simplified | FileCheck --check-prefix=SIMPL %s
+; RUN: llc <%s -jump-table-type=full | FileCheck --check-prefix=FULL %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.fun_struct = type { i32 (...)* }
+
+define void @indirect_fun() unnamed_addr jumptable {
+  ret void
+}
+
+define void @indirect_fun_match() unnamed_addr jumptable {
+  ret void
+}
+
+define i32 @indirect_fun_i32() unnamed_addr jumptable {
+  ret i32 0
+}
+
+define i32 @indirect_fun_i32_1(i32 %a) unnamed_addr jumptable {
+  ret i32 %a
+}
+
+define i32 @indirect_fun_i32_2(i32 %a, i32 %b) unnamed_addr jumptable {
+  ret i32 %a
+}
+
+define i32* @indirect_fun_i32S_2(i32* %a, i32 %b) unnamed_addr jumptable {
+  ret i32* %a
+}
+
+define void @indirect_fun_struct(%struct.fun_struct %fs) unnamed_addr jumptable {
+  ret void
+}
+
+define void @indirect_fun_fun(i32 (...)* %fun, i32 %a) unnamed_addr jumptable {
+  ret void
+}
+
+define i32 @indirect_fun_fun_ret(i32 (...)* %fun, i32 %a) unnamed_addr jumptable {
+  ret i32 %a
+}
+
+define void @indirect_fun_array([19 x i8] %a) unnamed_addr jumptable {
+  ret void
+}
+
+define void @indirect_fun_vec(<3 x i32> %a) unnamed_addr jumptable {
+  ret void
+}
+
+define void @indirect_fun_vec_2(<4 x float> %a) unnamed_addr jumptable {
+  ret void
+}
+
+define i32 @m(void ()* %fun) {
+  call void ()* %fun()
+  ret i32 0
+}
+
+define void ()* @get_fun() {
+  ret void ()* @indirect_fun
+; SINGLE: movl    $__llvm_jump_instr_table_0_
+; ARITY: movl    $__llvm_jump_instr_table_
+; SIMPL: movl    $__llvm_jump_instr_table_
+; FULL: movl    $__llvm_jump_instr_table_
+}
+
+define i32 @main(i32 %argc, i8** %argv) {
+  %f = call void ()* ()* @get_fun()
+  %a = call i32 @m(void ()* %f)
+  ret i32 %a
+}
+
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_1
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_1,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_1:
+; SINGLE-DAG:         jmp     indirect_fun_array@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_2
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_2,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_2:
+; SINGLE-DAG:         jmp     indirect_fun_i32_2@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_3
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_3,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_3:
+; SINGLE-DAG:         jmp     indirect_fun_vec_2@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_4
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_4,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_4:
+; SINGLE-DAG:         jmp     indirect_fun_i32S_2@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_5
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_5,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_5:
+; SINGLE-DAG:         jmp     indirect_fun_struct@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_6
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_6,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_6:
+; SINGLE-DAG:         jmp     indirect_fun_i32_1@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_7
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_7,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_7:
+; SINGLE-DAG:         jmp     indirect_fun_i32@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_8
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_8,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_8:
+; SINGLE-DAG:         jmp     indirect_fun_fun@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_9
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_9,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_9:
+; SINGLE-DAG:         jmp     indirect_fun_fun_ret@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_10
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_10,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_10:
+; SINGLE-DAG:         jmp     indirect_fun@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_11
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_11,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_11:
+; SINGLE-DAG:         jmp     indirect_fun_match@PLT
+; SINGLE-DAG:         .globl  __llvm_jump_instr_table_0_12
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         .type   __llvm_jump_instr_table_0_12,@function
+; SINGLE-DAG: __llvm_jump_instr_table_0_12:
+; SINGLE-DAG:         jmp     indirect_fun_vec@PLT
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         ud2
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         ud2
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         ud2
+; SINGLE-DAG:         .align  8, 0x90
+; SINGLE-DAG:         ud2
+
+
+; ARITY-DAG:         .globl  __llvm_jump_instr_table_2_1
+; ARITY-DAG:         .align  8, 0x90
+; ARITY-DAG:         .type   __llvm_jump_instr_table_2_1,@function
+; ARITY-DAG: __llvm_jump_instr_table_2_1:
+; ARITY-DAG:         jmp     indirect_fun{{.*}}@PLT
+; ARITY-DAG:         .align  8, 0x90
+; ARITY-DAG:         ud2
+; ARITY-DAG:         .globl  __llvm_jump_instr_table_0_1
+; ARITY-DAG:         .align  8, 0x90
+; ARITY-DAG:         .type   __llvm_jump_instr_table_0_1,@function
+; ARITY-DAG: __llvm_jump_instr_table_0_1:
+; ARITY-DAG:         jmp     indirect_fun{{.*}}@PLT
+; ARITY-DAG:         .globl  __llvm_jump_instr_table_1_1
+; ARITY-DAG:         .align  8, 0x90
+; ARITY-DAG:         .type   __llvm_jump_instr_table_1_1,@function
+; ARITY-DAG: __llvm_jump_instr_table_1_1:
+; ARITY-DAG:         jmp     indirect_fun{{.*}}@PLT
+
+; SIMPL-DAG:         .globl  __llvm_jump_instr_table_2_1
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         .type   __llvm_jump_instr_table_2_1,@function
+; SIMPL-DAG: __llvm_jump_instr_table_2_1:
+; SIMPL-DAG:         jmp     indirect_fun{{.*}}@PLT
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         ud2
+; SIMPL-DAG:         .globl  __llvm_jump_instr_table_0_1
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         .type   __llvm_jump_instr_table_0_1,@function
+; SIMPL-DAG: __llvm_jump_instr_table_0_1:
+; SIMPL-DAG:         jmp     indirect_fun{{.*}}@PLT
+; SIMPL-DAG:         .globl  __llvm_jump_instr_table_1_1
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         .type   __llvm_jump_instr_table_1_1,@function
+; SIMPL-DAG: __llvm_jump_instr_table_1_1:
+; SIMPL-DAG:         jmp     indirect_fun{{.*}}@PLT
+; SIMPL-DAG:         .globl  __llvm_jump_instr_table_3_1
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         .type   __llvm_jump_instr_table_3_1,@function
+; SIMPL-DAG: __llvm_jump_instr_table_3_1:
+; SIMPL-DAG:         jmp     indirect_fun{{.*}}@PLT
+; SIMPL-DAG:         .globl  __llvm_jump_instr_table_4_1
+; SIMPL-DAG:         .align  8, 0x90
+; SIMPL-DAG:         .type   __llvm_jump_instr_table_4_1,@function
+; SIMPL-DAG: __llvm_jump_instr_table_4_1:
+; SIMPL-DAG:         jmp     indirect_fun{{.*}}@PLT
+
+
+; FULL-DAG:        .globl  __llvm_jump_instr_table_10_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_10_1,@function
+; FULL-DAG:__llvm_jump_instr_table_10_1:
+; FULL-DAG:        jmp     indirect_fun_i32_1@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_9_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_9_1,@function
+; FULL-DAG:__llvm_jump_instr_table_9_1:
+; FULL-DAG:        jmp     indirect_fun_i32_2@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_7_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_7_1,@function
+; FULL-DAG:__llvm_jump_instr_table_7_1:
+; FULL-DAG:        jmp     indirect_fun_i32S_2@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_3_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_3_1,@function
+; FULL-DAG:__llvm_jump_instr_table_3_1:
+; FULL-DAG:        jmp     indirect_fun_vec_2@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_2_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_2_1,@function
+; FULL-DAG:__llvm_jump_instr_table_2_1:
+; FULL-DAG:        jmp     indirect_fun@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_8_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_8_1,@function
+; FULL-DAG:__llvm_jump_instr_table_8_1:
+; FULL-DAG:        jmp     indirect_fun_i32@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_1_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_1_1,@function
+; FULL-DAG:__llvm_jump_instr_table_1_1:
+; FULL-DAG:        jmp     indirect_fun_array@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_0_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_0_1,@function
+; FULL-DAG:__llvm_jump_instr_table_0_1:
+; FULL-DAG:        jmp     indirect_fun_vec@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_6_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_6_1,@function
+; FULL-DAG:__llvm_jump_instr_table_6_1:
+; FULL-DAG:        jmp     indirect_fun_struct@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_5_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_5_1,@function
+; FULL-DAG:__llvm_jump_instr_table_5_1:
+; FULL-DAG:        jmp     indirect_fun_fun@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2
+; FULL-DAG:        .globl  __llvm_jump_instr_table_4_1
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        .type   __llvm_jump_instr_table_4_1,@function
+; FULL-DAG:__llvm_jump_instr_table_4_1:
+; FULL-DAG:        jmp     indirect_fun_fun_ret@PLT
+; FULL-DAG:        .align  8, 0x90
+; FULL-DAG:        ud2