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-rw-r--r--lld/ELF/ICF.cpp84
-rw-r--r--lld/test/ELF/Inputs/icf-merge-sec.s9
-rw-r--r--lld/test/ELF/Inputs/icf-merge.s10
-rw-r--r--lld/test/ELF/Inputs/icf-merge2.s10
-rw-r--r--lld/test/ELF/Inputs/icf-merge3.s10
-rw-r--r--lld/test/ELF/icf-merge-sec.s18
-rw-r--r--lld/test/ELF/icf-merge.s27
7 files changed, 146 insertions, 22 deletions
diff --git a/lld/ELF/ICF.cpp b/lld/ELF/ICF.cpp
index 536032bdc3a..09512a8b09d 100644
--- a/lld/ELF/ICF.cpp
+++ b/lld/ELF/ICF.cpp
@@ -98,7 +98,8 @@ private:
void segregate(size_t Begin, size_t End, bool Constant);
template <class RelTy>
- bool constantEq(ArrayRef<RelTy> RelsA, ArrayRef<RelTy> RelsB);
+ bool constantEq(const InputSection *A, ArrayRef<RelTy> RelsA,
+ const InputSection *B, ArrayRef<RelTy> RelsB);
template <class RelTy>
bool variableEq(const InputSection *A, ArrayRef<RelTy> RelsA,
@@ -206,11 +207,53 @@ void ICF<ELFT>::segregate(size_t Begin, size_t End, bool Constant) {
// Compare two lists of relocations.
template <class ELFT>
template <class RelTy>
-bool ICF<ELFT>::constantEq(ArrayRef<RelTy> RelsA, ArrayRef<RelTy> RelsB) {
- auto Eq = [](const RelTy &A, const RelTy &B) {
- return A.r_offset == B.r_offset &&
- A.getType(Config->IsMips64EL) == B.getType(Config->IsMips64EL) &&
- getAddend<ELFT>(A) == getAddend<ELFT>(B);
+bool ICF<ELFT>::constantEq(const InputSection *A, ArrayRef<RelTy> RelsA,
+ const InputSection *B, ArrayRef<RelTy> RelsB) {
+ auto Eq = [&](const RelTy &RA, const RelTy &RB) {
+ if (RA.r_offset != RB.r_offset ||
+ RA.getType(Config->IsMips64EL) != RB.getType(Config->IsMips64EL))
+ return false;
+ uint64_t AddA = getAddend<ELFT>(RA);
+ uint64_t AddB = getAddend<ELFT>(RB);
+
+ SymbolBody &SA = A->template getFile<ELFT>()->getRelocTargetSym(RA);
+ SymbolBody &SB = B->template getFile<ELFT>()->getRelocTargetSym(RB);
+ if (&SA == &SB)
+ return AddA == AddB;
+
+ auto *DA = dyn_cast<DefinedRegular>(&SA);
+ auto *DB = dyn_cast<DefinedRegular>(&SB);
+ if (!DA || !DB)
+ return false;
+
+ // Relocations referring to absolute symbols are constant-equal if their
+ // values are equal.
+ if (!DA->Section || !DB->Section)
+ return !DA->Section && !DB->Section &&
+ DA->Value + AddA == DB->Value + AddB;
+
+ if (DA->Section->kind() != DB->Section->kind())
+ return false;
+
+ // Relocations referring to InputSections are constant-equal if their
+ // section offsets are equal.
+ if (isa<InputSection>(DA->Section))
+ return DA->Value + AddA == DB->Value + AddB;
+
+ // Relocations referring to MergeInputSections are constant-equal if their
+ // offsets in the output section are equal.
+ auto *X = dyn_cast<MergeInputSection>(DA->Section);
+ if (!X)
+ return false;
+ auto *Y = cast<MergeInputSection>(DB->Section);
+ if (X->getParent() != Y->getParent())
+ return false;
+
+ uint64_t OffsetA =
+ SA.isSection() ? X->getOffset(AddA) : X->getOffset(DA->Value) + AddA;
+ uint64_t OffsetB =
+ SB.isSection() ? Y->getOffset(AddB) : Y->getOffset(DB->Value) + AddB;
+ return OffsetA == OffsetB;
};
return RelsA.size() == RelsB.size() &&
@@ -226,8 +269,9 @@ bool ICF<ELFT>::equalsConstant(const InputSection *A, const InputSection *B) {
return false;
if (A->AreRelocsRela)
- return constantEq(A->template relas<ELFT>(), B->template relas<ELFT>());
- return constantEq(A->template rels<ELFT>(), B->template rels<ELFT>());
+ return constantEq(A, A->template relas<ELFT>(), B,
+ B->template relas<ELFT>());
+ return constantEq(A, A->template rels<ELFT>(), B, B->template rels<ELFT>());
}
// Compare two lists of relocations. Returns true if all pairs of
@@ -243,22 +287,18 @@ bool ICF<ELFT>::variableEq(const InputSection *A, ArrayRef<RelTy> RelsA,
if (&SA == &SB)
return true;
- auto *DA = dyn_cast<DefinedRegular>(&SA);
- auto *DB = dyn_cast<DefinedRegular>(&SB);
- if (!DA || !DB)
- return false;
- if (DA->Value != DB->Value)
- return false;
-
- // Either both symbols must be absolute...
- if (!DA->Section || !DB->Section)
- return !DA->Section && !DB->Section;
+ auto *DA = cast<DefinedRegular>(&SA);
+ auto *DB = cast<DefinedRegular>(&SB);
- // Or the two sections must be in the same equivalence class.
+ // We already dealt with absolute and non-InputSection symbols in
+ // constantEq, and for InputSections we have already checked everything
+ // except the equivalence class.
+ if (!DA->Section)
+ return true;
auto *X = dyn_cast<InputSection>(DA->Section);
- auto *Y = dyn_cast<InputSection>(DB->Section);
- if (!X || !Y)
- return false;
+ if (!X)
+ return true;
+ auto *Y = cast<InputSection>(DB->Section);
// Ineligible sections are in the special equivalence class 0.
// They can never be the same in terms of the equivalence class.
diff --git a/lld/test/ELF/Inputs/icf-merge-sec.s b/lld/test/ELF/Inputs/icf-merge-sec.s
new file mode 100644
index 00000000000..7454e952e38
--- /dev/null
+++ b/lld/test/ELF/Inputs/icf-merge-sec.s
@@ -0,0 +1,9 @@
+.section .rodata.str,"aMS",@progbits,1
+.asciz "bar"
+.asciz "baz"
+.asciz "foo"
+
+.section .text.f2,"ax"
+.globl f2
+f2:
+.quad .rodata.str+8
diff --git a/lld/test/ELF/Inputs/icf-merge.s b/lld/test/ELF/Inputs/icf-merge.s
new file mode 100644
index 00000000000..8a099298f5c
--- /dev/null
+++ b/lld/test/ELF/Inputs/icf-merge.s
@@ -0,0 +1,10 @@
+.section .rodata.str,"aMS",@progbits,1
+.asciz "bar"
+.asciz "baz"
+foo:
+.asciz "foo"
+
+.section .text.f2,"ax"
+.globl f2
+f2:
+lea foo+42(%rip), %rax
diff --git a/lld/test/ELF/Inputs/icf-merge2.s b/lld/test/ELF/Inputs/icf-merge2.s
new file mode 100644
index 00000000000..e845a6177e2
--- /dev/null
+++ b/lld/test/ELF/Inputs/icf-merge2.s
@@ -0,0 +1,10 @@
+.section .rodata.str,"aMS",@progbits,1
+.asciz "bar"
+.asciz "baz"
+boo:
+.asciz "boo"
+
+.section .text.f2,"ax"
+.globl f2
+f2:
+lea boo+42(%rip), %rax
diff --git a/lld/test/ELF/Inputs/icf-merge3.s b/lld/test/ELF/Inputs/icf-merge3.s
new file mode 100644
index 00000000000..91bf05ebea2
--- /dev/null
+++ b/lld/test/ELF/Inputs/icf-merge3.s
@@ -0,0 +1,10 @@
+.section .rodata.str,"aMS",@progbits,1
+.asciz "bar"
+.asciz "baz"
+foo:
+.asciz "foo"
+
+.section .text.f2,"ax"
+.globl f2
+f2:
+lea foo+43(%rip), %rax
diff --git a/lld/test/ELF/icf-merge-sec.s b/lld/test/ELF/icf-merge-sec.s
new file mode 100644
index 00000000000..39f6a884fa9
--- /dev/null
+++ b/lld/test/ELF/icf-merge-sec.s
@@ -0,0 +1,18 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/icf-merge-sec.s -o %t2
+# RUN: ld.lld %t %t2 -o %t3 --icf=all --verbose | FileCheck %s
+
+# CHECK: selected .text.f1
+# CHECK: removed .text.f2
+
+.section .rodata.str,"aMS",@progbits,1
+.asciz "foo"
+.asciz "string 1"
+.asciz "string 2"
+
+.section .text.f1,"ax"
+.globl f1
+f1:
+.quad .rodata.str
diff --git a/lld/test/ELF/icf-merge.s b/lld/test/ELF/icf-merge.s
new file mode 100644
index 00000000000..938b749da6b
--- /dev/null
+++ b/lld/test/ELF/icf-merge.s
@@ -0,0 +1,27 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/icf-merge.s -o %t1
+# RUN: ld.lld %t %t1 -o %t1.out --icf=all --verbose | FileCheck %s
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/icf-merge2.s -o %t2
+# RUN: ld.lld %t %t2 -o %t3.out --icf=all --verbose | FileCheck --check-prefix=NOMERGE %s
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/icf-merge3.s -o %t3
+# RUN: ld.lld %t %t3 -o %t3.out --icf=all --verbose | FileCheck --check-prefix=NOMERGE %s
+
+# CHECK: selected .text.f1
+# CHECK: removed .text.f2
+
+# NOMERGE-NOT: selected .text.f
+
+.section .rodata.str,"aMS",@progbits,1
+foo:
+.asciz "foo"
+.asciz "string 1"
+.asciz "string 2"
+
+.section .text.f1,"ax"
+.globl f1
+f1:
+lea foo+42(%rip), %rax
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