[lld][Hexagon] Fix R_HEX_TPREL_11_X relocation on duplex instructions (llvm#179860)

androm3da · c-rhodes · commit 4688b97ecddb · 2026-02-11T10:06:53.000Z
findMaskR11() was missing handling for duplex instructions. This caused incorrect encoding when R_HEX_TPREL_11_X relocations were applied to duplex instructions with large TLS offsets. For duplex instructions, the immediate bits are located at positions 20-25 (mask 0x03f00000), not in the standard positions used for non-duplex instructions. This fix adds the isDuplex() check to findMaskR11() to return the correct mask for duplex instruction encodings. (cherry picked from commit 62d018b)
diff --git a/lld/ELF/Arch/Hexagon.cpp b/lld/ELF/Arch/Hexagon.cpp
@@ -225,6 +225,8 @@ static uint32_t findMaskR8(uint32_t insn) {
 }
 
 static uint32_t findMaskR11(uint32_t insn) {
+  if (isDuplex(insn))
+    return 0x03f00000;
   if ((0xff000000 & insn) == 0xa1000000)
     return 0x060020ff;
   return 0x06003fe0;
diff --git a/lld/test/ELF/hexagon-tls-ie.s b/lld/test/ELF/hexagon-tls-ie.s
@@ -1,5 +1,6 @@
 # REQUIRES: hexagon
-# RUN: llvm-mc -filetype=obj -triple=hexagon-unknown-elf %s -o %t.o
+# RUN: rm -rf %t.dir && split-file %s %t.dir
+# RUN: llvm-mc -filetype=obj -triple=hexagon-unknown-elf %t.dir/main.s -o %t.o
 # RUN: llvm-readobj -r %t.o | FileCheck -check-prefix=RELOC %s
 # RUN: ld.lld %t.o -o %t
 ## shared needs -z notext because of the R_HEX_IE_16/32_X(R_GOT) static
@@ -11,6 +12,16 @@
 # RUN: FileCheck -check-prefix=SHARED %s
 # RUN: llvm-readobj -r  %t.so | FileCheck -check-prefix=RELA %s
 
+## Test R_HEX_TPREL_11_X on duplex instructions with large TLS offset.
+## TPREL relocations cannot be used with -shared, so test separately.
+# RUN: llvm-mc -filetype=obj -triple=hexagon-unknown-elf \
+# RUN:   %t.dir/tprel-duplex.s -o %t-duplex.o
+# RUN: llvm-readobj -r %t-duplex.o | FileCheck -check-prefix=RELOC-DUPLEX %s
+# RUN: ld.lld %t-duplex.o -o %t-duplex
+# RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex %t-duplex | \
+# RUN:   FileCheck -check-prefix=CHECK-DUPLEX %s
+
+#--- main.s
 	.globl	_start
 	.type	_start, @function
 _start:
@@ -76,3 +87,26 @@ c:
 .globl  d
 d:
 .word 4
+
+#--- tprel-duplex.s
+## Test R_HEX_TPREL_11_X on duplex instructions with large TLS offset.
+## This exercises the isDuplex() path in findMaskR11().
+	.globl	_start
+	.type	_start, @function
+_start:
+# RELOC-DUPLEX:      0x0 R_HEX_TPREL_32_6_X e 0x0
+# RELOC-DUPLEX-NEXT: 0x4 R_HEX_TPREL_11_X e 0x0
+# CHECK-DUPLEX:      { immext(#0xfffbffc0)
+# CHECK-DUPLEX-NEXT:   r2 = add(r2,##-0x40003); memw(r3+#0x0) = #0 }
+    {
+        r2 = add(r2,##e@TPREL)
+        memw(r3+#0) = #0
+    }
+    jumpr r31
+
+.section .tbss,"awT",@nobits
+.p2align 2
+.space 0xd
+.globl e
+e:
+.space 0x40000

Original file line number	Diff line number	Diff line change
`@@ -225,6 +225,8 @@ static uint32_t findMaskR8(uint32_t insn) {`
`225`	`225`	`}`
`226`	`226`
`227`	`227`	`static uint32_t findMaskR11(uint32_t insn) {`
	`228`	`+ if (isDuplex(insn))`
	`229`	`+ return 0x03f00000;`
`228`	`230`	`if ((0xff000000 & insn) == 0xa1000000)`
`229`	`231`	`return 0x060020ff;`
`230`	`232`	`return 0x06003fe0;`