[lld] [lld][LoongArch] Support the R_LARCH_CALL36 relocation type (PR #73346)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,40 @@
+# REQUIRES: loongarch
+
+# RUN: llvm-mc --filetype=obj --triple=loongarch64-unknown-elf %s -o %t.o
+
+# RUN: ld.lld %t.o --section-start=.text=0x20010 --section-start=.sec.foo=0x60020 -o %t1
+# RUN: llvm-objdump --no-show-raw-insn -d %t1 | FileCheck --match-full-lines %s --check-prefix=CASE1
+## hi20 = target - pc + (1 << 17) >> 18 = 0x60020 - 0x20010 + 0x20000 >> 18 = 1
+## lo18 = target - pc & (1 << 18) - 1 = 0x60020 - 0x20010 & 0x3ffff = 16
+# CASE1:      20010: pcaddu18i $ra, 1
+# CASE1-NEXT: 20014: jirl $zero, $ra, 16
+
+# RUN: ld.lld %t.o --section-start=.text=0x20010 --section-start=.sec.foo=0x40020 -o %t2
+# RUN: llvm-objdump --no-show-raw-insn -d %t2 | FileCheck --match-full-lines %s --check-prefix=CASE2
+## hi20 = target - pc + (1 << 17) >> 18 = 0x40020 - 0x20010 + 0x20000 >> 18 = 1
+## lo18 = target - pc & (1 << 18) - 1 = 0x40020 - 0x20010 & 0x3ffff = -131056
+# CASE2:      20010: pcaddu18i $ra, 1
+# CASE2-NEXT: 20014: jirl $zero, $ra, -131056
+
+# RUN: not ld.lld %t.o --section-start=.text=0x20000 --section-start=.sec.foo=0x2000020000 -o /dev/null 2>&1 | \
+# RUN:   FileCheck -DFILE=%t.o --check-prefix=ERROR-RANGE %s
+# ERROR-RANGE: error: [[FILE]]:(.text+0x0): relocation R_LARCH_CALL36 out of range: 137438953472 is not in [-137438953472, 137438953471]; references 'foo'
+
+## Impossible case in reality becasue all LoongArch instructions are fixed 4-bytes long.
+# RUN: not ld.lld %t.o --section-start=.text=0x20000 --section-start=.sec.foo=0x40001 -o /dev/null 2>&1 | \
+# RUN:   FileCheck -DFILE=%t.o --check-prefix=ERROR-ALIGN %s
+# ERROR-ALIGN: error: [[FILE]]:(.text+0x0): improper alignment for relocation R_LARCH_CALL36: 0x20001 is not aligned to 4 bytes
+
+.text
+.global _start
+_start:
+1:
+  pcaddu18i $ra, 0
+  jirl $zero, $ra, 0
+  .reloc 1b, R_LARCH_CALL36, foo
+
+.section .sec.foo,"ax"
+.global foo
+foo:
+  nop
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MaskRay wrote:

delete nop if unused

https://github.com/llvm/llvm-project/pull/73346