[llvm-branch-commits] [lld] [lld][LoongArch] Support relaxation during TLSDESC GD/LD to IE/LE conversion. (PR #123730)
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llvm-branch-commits at lists.llvm.org
Tue Jan 21 03:00:56 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-lld-elf
@llvm/pr-subscribers-lld
Author: Zhaoxin Yang (ylzsx)
<details>
<summary>Changes</summary>
Complement https://github.com/llvm/llvm-project/pull/123715. When relaxation enable, remove redundant NOPs.
---
Full diff: https://github.com/llvm/llvm-project/pull/123730.diff
2 Files Affected:
- (modified) lld/ELF/Arch/LoongArch.cpp (+29-3)
- (modified) lld/test/ELF/loongarch-relax-tlsdesc.s (+16-29)
``````````diff
diff --git a/lld/ELF/Arch/LoongArch.cpp b/lld/ELF/Arch/LoongArch.cpp
index 37614c3e9615d6..5f49b23e8ffb1a 100644
--- a/lld/ELF/Arch/LoongArch.cpp
+++ b/lld/ELF/Arch/LoongArch.cpp
@@ -965,10 +965,16 @@ static bool relax(Ctx &ctx, InputSection &sec) {
case R_LARCH_GOT_PC_HI20:
case R_LARCH_TLS_GD_PC_HI20:
case R_LARCH_TLS_LD_PC_HI20:
- case R_LARCH_TLS_DESC_PC_HI20:
// The overflow check for i+2 will be carried out in isPairRelaxable.
- if (r.expr != RE_LOONGARCH_RELAX_TLS_GD_TO_IE_PAGE_PC &&
- r.expr != R_RELAX_TLS_GD_TO_LE && isPairRelaxable(relocs, i))
+ if (isPairRelaxable(relocs, i))
+ relaxPCHi20Lo12(ctx, sec, i, loc, r, relocs[i + 2], remove);
+ break;
+ case R_LARCH_TLS_DESC_PC_HI20:
+ if (r.expr == RE_LOONGARCH_RELAX_TLS_GD_TO_IE_PAGE_PC ||
+ r.expr == R_RELAX_TLS_GD_TO_LE) {
+ if (relaxable(relocs, i))
+ remove = 4;
+ } else if (isPairRelaxable(relocs, i))
relaxPCHi20Lo12(ctx, sec, i, loc, r, relocs[i + 2], remove);
break;
case R_LARCH_CALL36:
@@ -986,6 +992,17 @@ static bool relax(Ctx &ctx, InputSection &sec) {
isUInt<12>(r.sym->getVA(ctx, r.addend)))
remove = 4;
break;
+ case R_LARCH_TLS_DESC_PC_LO12:
+ if (relaxable(relocs, i) &&
+ (r.expr == RE_LOONGARCH_RELAX_TLS_GD_TO_IE_PAGE_PC ||
+ r.expr == R_RELAX_TLS_GD_TO_LE))
+ remove = 4;
+ break;
+ case R_LARCH_TLS_DESC_LD:
+ if (relaxable(relocs, i) && r.expr == R_RELAX_TLS_GD_TO_LE &&
+ isUInt<12>(r.sym->getVA(ctx, r.addend)))
+ remove = 4;
+ break;
}
// For all anchors whose offsets are <= r.offset, they are preceded by
@@ -1214,6 +1231,10 @@ void LoongArch::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const {
bits);
relocateNoSym(loc, rel.type, val);
} else {
+ isRelax = relaxable(relocs, i);
+ if (isRelax && (rel.type == R_LARCH_TLS_DESC_PC_HI20 ||
+ rel.type == R_LARCH_TLS_DESC_PC_LO12))
+ continue;
tlsdescToIe(loc, rel, val);
}
continue;
@@ -1230,6 +1251,11 @@ void LoongArch::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const {
bits);
relocateNoSym(loc, rel.type, val);
} else {
+ isRelax = relaxable(relocs, i);
+ if (isRelax && (rel.type == R_LARCH_TLS_DESC_PC_HI20 ||
+ rel.type == R_LARCH_TLS_DESC_PC_LO12 ||
+ (rel.type == R_LARCH_TLS_DESC_LD && isUInt<12>(val))))
+ continue;
tlsdescToLe(loc, rel, val);
}
continue;
diff --git a/lld/test/ELF/loongarch-relax-tlsdesc.s b/lld/test/ELF/loongarch-relax-tlsdesc.s
index 5e538985d1402c..666ca6bd1e7243 100644
--- a/lld/test/ELF/loongarch-relax-tlsdesc.s
+++ b/lld/test/ELF/loongarch-relax-tlsdesc.s
@@ -9,7 +9,6 @@
# RUN: llvm-readobj -r -x .got a.64.so | FileCheck --check-prefix=GD64-RELA %s
# RUN: llvm-objdump --no-show-raw-insn -dr -h a.64.so | FileCheck %s --check-prefix=GD64
-## FIXME: IE/LE relaxation have not yet been implemented, --relax/--no-relax obtain the same results.
## Transition from TLSDESC to IE/LE. Also check --emit-relocs.
# RUN: ld.lld --relax -e 0 -z now --emit-relocs a.64.o c.64.o -o a.64.le
# RUN: llvm-readobj -r -x .got a.64.le 2>&1 | FileCheck --check-prefix=LE64-RELA %s
@@ -73,25 +72,21 @@
# LE64-RELA: could not find section '.got'
## a at tprel = 0x8
-# LE64: 20158: nop
+# LE64: 20158: ori $a0, $zero, 8
# LE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 a
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: nop
# LE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 a
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: nop
# LE64-NEXT: R_LARCH_TLS_DESC_LD a
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: ori $a0, $zero, 8
# LE64-NEXT: R_LARCH_TLS_DESC_CALL a
# LE64-NEXT: R_LARCH_RELAX *ABS*
# LE64-NEXT: add.d $a1, $a0, $tp
## b at tprel = 0x7ff
-# LE64: 2016c: nop
+# LE64: 20160: nop
# LE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 b
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: nop
# LE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 b
# LE64-NEXT: nop
# LE64-NEXT: R_LARCH_TLS_DESC_LD b
@@ -101,7 +96,7 @@
## c at tprel = 0x800
## Without R_LARCH_RELAX relocation. No relaxation.
-# LE64: 20180: nop
+# LE64: 20170: nop
# LE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 c
# LE64-NEXT: addi.d $t0, $zero, 0
# LE64-NEXT: nop
@@ -115,13 +110,11 @@
# LE64-NEXT: add.d $a3, $a0, $tp
## d at tprel = 0x1000
-# LE64: 201a0: nop
+# LE64: 20190: lu12i.w $a0, 1
# LE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 d
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: nop
# LE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 d
# LE64-NEXT: R_LARCH_RELAX *ABS*
-# LE64-NEXT: lu12i.w $a0, 1
# LE64-NEXT: R_LARCH_TLS_DESC_LD d
# LE64-NEXT: ori $a0, $a0, 0
# LE64-NEXT: R_LARCH_TLS_DESC_CALL d
@@ -160,35 +153,31 @@
# LE64-NORELAX-NEXT: add.d $a4, $a0, $tp
# IE64-RELA: .rela.dyn {
-# IE64-RELA-NEXT: 0x30408 R_LARCH_TLS_TPREL64 c 0x0
-# IE64-RELA-NEXT: 0x30410 R_LARCH_TLS_TPREL64 d 0x0
+# IE64-RELA-NEXT: 0x303F0 R_LARCH_TLS_TPREL64 c 0x0
+# IE64-RELA-NEXT: 0x303F8 R_LARCH_TLS_TPREL64 d 0x0
# IE64-RELA-NEXT: }
# IE64-RELA: Hex dump of section '.got':
-# IE64-RELA-NEXT: 0x00030408 00000000 00000000 00000000 00000000 .
+# IE64-RELA-NEXT: 0x000303f0 00000000 00000000 00000000 00000000 .
-# IE64: .got 00000010 0000000000030408
+# IE64: .got 00000010 00000000000303f0
## a and b are optimized to use LE. c and d are optimized to IE.
## a at tprel = 0x8
-# IE64: 202c8: nop
+# IE64: 202c8: ori $a0, $zero, 8
# IE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 a
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: nop
# IE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 a
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: nop
# IE64-NEXT: R_LARCH_TLS_DESC_LD a
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: ori $a0, $zero, 8
# IE64-NEXT: R_LARCH_TLS_DESC_CALL a
# IE64-NEXT: R_LARCH_RELAX *ABS*
# IE64-NEXT: add.d $a1, $a0, $tp
## b at tprel = 0x7ff
-# IE64: 202dc: nop
+# IE64: 202d0: nop
# IE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 b
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: nop
# IE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 b
# IE64-NEXT: nop
# IE64-NEXT: R_LARCH_TLS_DESC_LD b
@@ -196,9 +185,9 @@
# IE64-NEXT: R_LARCH_TLS_DESC_CALL b
# IE64-NEXT: add.d $a2, $a0, $tp
-## &.got[c]-. = 0x30408 - 0x20300: 0x10 pages, page offset 0x408
+## &.got[c]-. = 0x303f0 - 0x202f0: 0x10 pages, page offset 0x3f0
## Without R_LARCH_RELAX relocation. No relaxation.
-# IE64: 202f0: nop
+# IE64: 202e0: nop
# IE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 c
# IE64-NEXT: addi.d $t0, $zero, 0
# IE64-NEXT: nop
@@ -207,20 +196,18 @@
# IE64-NEXT: pcalau12i $a0, 16
# IE64-NEXT: R_LARCH_TLS_DESC_LD c
# IE64-NEXT: addi.d $t0, $t0, 1
-# IE64-NEXT: ld.d $a0, $a0, 1032
+# IE64-NEXT: ld.d $a0, $a0, 1008
# IE64-NEXT: R_LARCH_TLS_DESC_CALL c
# IE64-NEXT: add.d $a3, $a0, $tp
-## &.got[d]-. = 0x30408+8 - 0x20318: 0x10 pages, page offset 0x410
-# IE64: 20310: nop
+## &.got[d]-. = 0x303f0+8 - 0x20300: 0x10 pages, page offset 0x3f8
+# IE64: 20300: pcalau12i $a0, 16
# IE64-NEXT: R_LARCH_TLS_DESC_PC_HI20 d
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: nop
# IE64-NEXT: R_LARCH_TLS_DESC_PC_LO12 d
# IE64-NEXT: R_LARCH_RELAX *ABS*
-# IE64-NEXT: pcalau12i $a0, 16
# IE64-NEXT: R_LARCH_TLS_DESC_LD d
-# IE64-NEXT: ld.d $a0, $a0, 1040
+# IE64-NEXT: ld.d $a0, $a0, 1016
# IE64-NEXT: R_LARCH_TLS_DESC_CALL d
# IE64-NEXT: add.d $a4, $a0, $tp
``````````
</details>
https://github.com/llvm/llvm-project/pull/123730
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