Extend the IL for selecting TLS models (PR9788)

This allows the user/front-end to specify a model that is better
than what LLVM would choose by default. For example, a variable
might be declared as

  @x = thread_local(initialexec) global i32 42

if it will not be used in a shared library that is dlopen'ed.

If the specified model isn't supported by the target, or if LLVM can
make a better choice, a different model may be used.

llvm-svn: 159077

1 files changed, 113 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/Mips/tls-models.ll b/llvm/test/CodeGen/Mips/tls-models.ll
new file mode 100644
index 00000000000..8f5789ec799
--- /dev/null
+++ b/llvm/test/CodeGen/Mips/tls-models.ll
@@ -0,0 +1,113 @@
+; RUN: llc -march=mipsel < %s | FileCheck -check-prefix=CHECK-PIC %s
+; RUN: llc -march=mipsel -relocation-model=static < %s | FileCheck -check-prefix=CHECK-NONPIC %s
+
+@external_gd = external thread_local global i32
+@internal_gd = internal thread_local global i32 42
+
+@external_ld = external thread_local(localdynamic) global i32
+@internal_ld = internal thread_local(localdynamic) global i32 42
+
+@external_ie = external thread_local(initialexec) global i32
+@internal_ie = internal thread_local(initialexec) global i32 42
+
+@external_le = external thread_local(localexec) global i32
+@internal_le = internal thread_local(localexec) global i32 42
+
+; ----- no model specified -----
+
+define i32* @f1() {
+entry:
+  ret i32* @external_gd
+
+  ; Non-PIC code can use initial-exec, PIC code has to use general dynamic.
+  ; CHECK-NONPIC:   f1:
+  ; CHECK-NONPIC:   %gottprel
+  ; CHECK-PIC:      f1:
+  ; CHECK-PIC:      %tlsgd
+}
+
+define i32* @f2() {
+entry:
+  ret i32* @internal_gd
+
+  ; Non-PIC code can use local exec, PIC code can use local dynamic.
+  ; CHECK-NONPIC:   f2:
+  ; CHECK-NONPIC:   %tprel_hi
+  ; CHECK-PIC:      f2:
+  ; CHECK-PIC:      %tlsldm
+}
+
+
+; ----- localdynamic specified -----
+
+define i32* @f3() {
+entry:
+  ret i32* @external_ld
+
+  ; Non-PIC code can use initial exec, PIC should use local dynamic.
+  ; CHECK-NONPIC:   f3:
+  ; CHECK-NONPIC:   %gottprel
+  ; CHECK-PIC:      f3:
+  ; CHECK-PIC:      %tlsldm
+}
+
+define i32* @f4() {
+entry:
+  ret i32* @internal_ld
+
+  ; Non-PIC code can use local exec, PIC code can use local dynamic.
+  ; CHECK-NONPIC:   f4:
+  ; CHECK-NONPIC:   %tprel_hi
+  ; CHECK-PIC:      f4:
+  ; CHECK-PIC:      %tlsldm
+}
+
+
+; ----- initialexec specified -----
+
+define i32* @f5() {
+entry:
+  ret i32* @external_ie
+
+  ; Non-PIC and PIC code will use initial exec as specified.
+  ; CHECK-NONPIC:   f5:
+  ; CHECK-NONPIC:   %gottprel
+  ; CHECK-PIC:      f5:
+  ; CHECK-PIC:      %gottprel
+}
+
+define i32* @f6() {
+entry:
+  ret i32* @internal_ie
+
+  ; Non-PIC code can use local exec, PIC code use initial exec as specified.
+  ; CHECK-NONPIC:   f6:
+  ; CHECK-NONPIC:   %tprel_hi
+  ; CHECK-PIC:      f6:
+  ; CHECK-PIC:      %gottprel
+}
+
+
+; ----- localexec specified -----
+
+define i32* @f7() {
+entry:
+  ret i32* @external_le
+
+  ; Non-PIC and PIC code will use local exec as specified.
+  ; CHECK-NONPIC:   f7:
+  ; CHECK-NONPIC:   %tprel_hi
+  ; CHECK-PIC:      f7:
+  ; CHECK-PIC:      %tprel_hi
+}
+
+define i32* @f8() {
+entry:
+  ret i32* @internal_le
+
+  ; Non-PIC and PIC code will use local exec as specified.
+  ; CHECK-NONPIC:   f8:
+  ; CHECK-NONPIC:   %tprel_hi
+  ; CHECK-PIC:      f8:
+  ; CHECK-PIC:      %tprel_hi
+}