[llvm] [PAC][CodeGen][ELF][AArch64] Support signed TLSDESC (PR #113813)

[Anatoly Trosinenko via llvm-commits]

================
@@ -0,0 +1,111 @@
+; RUN: llc -mtriple=aarch64-unknown-linux-gnu -mattr=+pauth -relocation-model=pic \
+; RUN:   -verify-machineinstrs < %s | FileCheck %s
+; RUN: llc -mtriple=aarch64-unknown-linux-gnu -mattr=+pauth -relocation-model=pic \
+; RUN:   -filetype=obj < %s | llvm-readelf -r -s - | FileCheck --check-prefix=CHECK-OBJ %s
+; RUN: not --crash llc -mtriple=aarch64-unknown-linux-gnu -mattr=+pauth -relocation-model=pic \
+; RUN:   -global-isel=1 < %s 2>&1 | FileCheck --check-prefix=CHECK-ERR %s
+
+ at general_dynamic_var = external thread_local global i32
+
+define i32 @test_generaldynamic() {
+; CHECK-LABEL: test_generaldynamic:
+
+  %val = load i32, ptr @general_dynamic_var
+  ret i32 %val
+
+; CHECK: adrp x[[TLSDESC_HI:[0-9]+]], :tlsdesc_auth:general_dynamic_var
+; CHECK-NEXT: ldr x16, [x[[TLSDESC_HI]], :tlsdesc_auth_lo12:general_dynamic_var]
+; CHECK-NEXT: add x0, x[[TLSDESC_HI]], :tlsdesc_auth_lo12:general_dynamic_var
+; CHECK-NEXT: blraa x16, x0
+; CHECK-NEXT: mrs x[[TPIDR:[0-9]+]], TPIDR_EL0
+; CHECK-NEXT: ldr w0, [x[[TPIDR]], x0]
+
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADR_PAGE21
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_LD64_LO12
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADD_LO12
+; CHECK-OBJ-NOT: R_AARCH64_TLSDESC_CALL
+
+; CHECK-ERR: LLVM ERROR: cannot select: %1:gpr64sp(p0) = G_GLOBAL_VALUE @general_dynamic_var (in function: test_generaldynamic)
+}
+
+define ptr @test_generaldynamic_addr() {
+; CHECK-LABEL: test_generaldynamic_addr:
+
+  ret ptr @general_dynamic_var
+
+; CHECK: adrp x[[TLSDESC_HI:[0-9]+]], :tlsdesc_auth:general_dynamic_var
+; CHECK-NEXT: ldr x16, [x[[TLSDESC_HI]], :tlsdesc_auth_lo12:general_dynamic_var]
+; CHECK-NEXT: add x0, x[[TLSDESC_HI]], :tlsdesc_auth_lo12:general_dynamic_var
+; CHECK-NEXT: blraa x16, x0
+; CHECK-NEXT: mrs [[TP:x[0-9]+]], TPIDR_EL0
+; CHECK-NEXT: add x0, [[TP]], x0
+
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADR_PAGE21
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_LD64_LO12
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADD_LO12
+; CHECK-OBJ-NOT: R_AARCH64_TLSDESC_CALL
+}
+
+ at local_dynamic_var = external thread_local(localdynamic) global i32
+
+define i32 @test_localdynamic() {
+; CHECK-LABEL: test_localdynamic:
+
+  %val = load i32, ptr @local_dynamic_var
+  ret i32 %val
+
+; CHECK: adrp x[[TLSDESC_HI:[0-9]+]], :tlsdesc_auth:local_dynamic_var
+; CHECK-NEXT: ldr x16, [x[[TLSDESC_HI]], :tlsdesc_auth_lo12:local_dynamic_var]
+; CHECK-NEXT: add x0, x[[TLSDESC_HI]], :tlsdesc_auth_lo12:local_dynamic_var
+; CHECK-NEXT: blraa x16, x0
+; CHECK-NEXT: mrs x[[TPIDR:[0-9]+]], TPIDR_EL0
+; CHECK-NEXT: ldr w0, [x[[TPIDR]], x0]
+
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADR_PAGE21
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_LD64_LO12
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADD_LO12
+; CHECK-OBJ-NOT: R_AARCH64_TLSDESC_CALL
+}
+
+define ptr @test_localdynamic_addr() {
+; CHECK-LABEL: test_localdynamic_addr:
+
+  ret ptr @local_dynamic_var
+
+; CHECK: adrp x[[TLSDESC_HI:[0-9]+]], :tlsdesc_auth:local_dynamic_var
+; CHECK-NEXT: ldr x16, [x[[TLSDESC_HI]], :tlsdesc_auth_lo12:local_dynamic_var]
+; CHECK-NEXT: add x0, x[[TLSDESC_HI]], :tlsdesc_auth_lo12:local_dynamic_var
+; CHECK-NEXT: blraa x16, x0
+; CHECK-NEXT: mrs x[[TPIDR:[0-9]+]], TPIDR_EL0
+; CHECK-NEXT: add x0, x[[TPIDR]], x0
+
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADR_PAGE21
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_LD64_LO12
+; CHECK-OBJ: R_AARCH64_AUTH_TLSDESC_ADD_LO12
+; CHECK-OBJ-NOT: R_AARCH64_TLSDESC_CALL
+}
+
+ at extern_weak_var = extern_weak thread_local global i32
+
+define i32 @test_extern_weak() {
+; CHECK-LABEL: test_extern_weak:
+
+  %val = load i32, ptr @extern_weak_var
+  ret i32 %val
+
+; CHECK: adrp x[[TLSDESC_HI:[0-9]+]], :tlsdesc_auth:extern_weak_var
+; CHECK-NEXT: ldr x16, [x[[TLSDESC_HI]], :tlsdesc_auth_lo12:extern_weak_var]
+; CHECK-NEXT: add x0, x[[TLSDESC_HI]], :tlsdesc_auth_lo12:extern_weak_var
+; CHECK-NEXT: blraa x16, x0
+; CHECK-NEXT: mrs x[[TPIDR:[0-9]+]], TPIDR_EL0
+; CHECK-NEXT: ldr w0, [x[[TPIDR]], x0]
----------------
atrosinenko wrote:

Got it, thank you! After all, if `extern_weak_var` is undefined, reading it would be UB anyway.

https://github.com/llvm/llvm-project/pull/113813