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[ELF][AsmPrinter] Emit trailing dot for constant pool section when it has a hotness prefix #150859

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Merged
merged 1 commit into from
Jul 30, 2025
Merged

[ELF][AsmPrinter] Emit trailing dot for constant pool section when it has a hotness prefix #150859

merged 1 commit into from
Jul 30, 2025

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@mingmingl-llvm mingmingl-llvm commented Jul 27, 2025 •
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Currently, TargetLoweringObjectFileELF::getSectionForConstant produce .<section>.hot or .<section>.unlikely for a constant with non-empty section prefix. This PR changes the implementation add trailing dot when section prefix is not empty, to disambiguate .hot as a hotness prefix from .hot as a (pure C) variable name.

Relevant discussions are in #148985 (comment) and #148985 (comment) and

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github-actions bot commented Jul 27, 2025 •
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✅ With the latest revision this PR passed the C/C++ code formatter.

@mingmingl-llvm mingmingl-llvm mentioned this pull request Jul 27, 2025
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@mingmingl-llvm mingmingl-llvm force-pushed the users/mingmingl-llvm/constantpool branch from 410cabe to 8e872ab Compare July 29, 2025 17:15
@mingmingl-llvm mingmingl-llvm marked this pull request as ready for review July 29, 2025 17:15
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llvmbot commented Jul 29, 2025

@llvm/pr-subscribers-backend-x86

Author: Mingming Liu (mingmingl-llvm)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/150859.diff

3 Files Affected:

  • (modified) llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (+7-7)
  • (modified) llvm/test/CodeGen/AArch64/constant-pool-partition.ll (+5-5)
  • (modified) llvm/test/CodeGen/X86/constant-pool-partition.ll (+4-4)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 670bf251ae8bc..61649751f4195 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1060,27 +1060,27 @@ MCSection *TargetLoweringObjectFileELF::getSectionForConstant(
 
   auto &Context = getContext();
   if (Kind.isMergeableConst4() && MergeableConst4Section)
-    return Context.getELFSection(".rodata.cst4." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst4." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 4);
   if (Kind.isMergeableConst8() && MergeableConst8Section)
-    return Context.getELFSection(".rodata.cst8." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst8." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 8);
   if (Kind.isMergeableConst16() && MergeableConst16Section)
-    return Context.getELFSection(".rodata.cst16." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst16." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 16);
   if (Kind.isMergeableConst32() && MergeableConst32Section)
-    return Context.getELFSection(".rodata.cst32." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst32." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 32);
   if (Kind.isReadOnly())
-    return Context.getELFSection(".rodata." + SectionSuffix, ELF::SHT_PROGBITS,
-                                 ELF::SHF_ALLOC);
+    return Context.getELFSection(".rodata." + SectionSuffix + ".",
+                                 ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 
   assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
-  return Context.getELFSection(".data.rel.ro." + SectionSuffix,
+  return Context.getELFSection(".data.rel.ro." + SectionSuffix + ".",
                                ELF::SHT_PROGBITS,
                                ELF::SHF_ALLOC | ELF::SHF_WRITE);
 }
diff --git a/llvm/test/CodeGen/AArch64/constant-pool-partition.ll b/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
index d4447131e9de1..9f4b3e21f22b5 100644
--- a/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
+++ b/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
@@ -19,11 +19,11 @@
 ;   function, constant pools for this constant should not have `.unlikely` suffix.
 
 ;; Constant pools for function @cold_func.
-; CHECK:       .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:       .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI0_0:
 ; CHECK-NEXT:	    .xword	0x3fe5c28f5c28f5c3              // double 0.68000000000000005
-; CHECK-NEXT: .section	.rodata.cst8.unlikely,"aM",@progbits,8
+; CHECK-NEXT: .section	.rodata.cst8.unlikely.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI0_1:
 ; CHECK-NEXT:     .xword 0x3fe5eb851eb851ec              // double 0.68500000000000005
@@ -58,7 +58,7 @@
 ; CHECK-NEXT:     .word 3                                 // 0x3
 ; CHECK-NEXT:     .word 5                                 // 0x5
 ; CHECK-NEXT:     .word 7                                 // 0x7
-; CHECK-NEXT: .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT: .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI1_2:
 ; CHECK-NEXT:     .word   442                             // 0x1ba
@@ -67,11 +67,11 @@
 ; CHECK-NEXT:     .word   0                               // 0x0
 
 ;; Constant pools for function @hot_func
-; CHECK:      .section        .rodata.cst8.hot,"aM",@progbits,8
+; CHECK:      .section        .rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI2_0:
 ; CHECK-NEXT:     .xword  0x3fe5c28f5c28f5c3              // double 0.68000000000000005
-; CHECK-NEXT: .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT: .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI2_1:
 ; CHECK-NEXT:     .word   0                               // 0x0
diff --git a/llvm/test/CodeGen/X86/constant-pool-partition.ll b/llvm/test/CodeGen/X86/constant-pool-partition.ll
index 515284fb2cf1a..e42b41b257651 100644
--- a/llvm/test/CodeGen/X86/constant-pool-partition.ll
+++ b/llvm/test/CodeGen/X86/constant-pool-partition.ll
@@ -24,11 +24,11 @@ target triple = "x86_64-grtev4-linux-gnu"
 ; RUN:     %s -o - 2>&1 | FileCheck %s --dump-input=always
 
 ;; For function @cold_func
-; CHECK:       .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:       .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI0_0:
 ; CHECK-NEXT:	     .quad	0x3fe5c28f5c28f5c3              # double 0.68000000000000005
-; CHECK-NEXT:  .section	.rodata.cst8.unlikely,"aM",@progbits,8
+; CHECK-NEXT:  .section	.rodata.cst8.unlikely.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI0_1:
 ; CHECK-NEXT:	     .quad	0x3eb0000000000000              # double 9.5367431640625E-7
@@ -50,11 +50,11 @@ target triple = "x86_64-grtev4-linux-gnu"
 ; CHECK-NEXT:     .long   0x3e000000              # float 0.125
 
 ;; For function @hot_func
-; CHECK:	     .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:	     .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI3_0:
 ; CHECK-NEXT:     .quad	0x3fe5c28f5c28f5c3              # double 0.68000000000000005
-; CHECK-NEXT:  .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT:  .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI3_1:
 ; CHECK-NEXT:      .long   2147483648                      # 0x80000000

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llvmbot commented Jul 29, 2025

@llvm/pr-subscribers-backend-aarch64

Author: Mingming Liu (mingmingl-llvm)

Changes

Full diff: https://github.com/llvm/llvm-project/pull/150859.diff

3 Files Affected:

  • (modified) llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (+7-7)
  • (modified) llvm/test/CodeGen/AArch64/constant-pool-partition.ll (+5-5)
  • (modified) llvm/test/CodeGen/X86/constant-pool-partition.ll (+4-4)
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 670bf251ae8bc..61649751f4195 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1060,27 +1060,27 @@ MCSection *TargetLoweringObjectFileELF::getSectionForConstant(
 
   auto &Context = getContext();
   if (Kind.isMergeableConst4() && MergeableConst4Section)
-    return Context.getELFSection(".rodata.cst4." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst4." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 4);
   if (Kind.isMergeableConst8() && MergeableConst8Section)
-    return Context.getELFSection(".rodata.cst8." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst8." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 8);
   if (Kind.isMergeableConst16() && MergeableConst16Section)
-    return Context.getELFSection(".rodata.cst16." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst16." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 16);
   if (Kind.isMergeableConst32() && MergeableConst32Section)
-    return Context.getELFSection(".rodata.cst32." + SectionSuffix,
+    return Context.getELFSection(".rodata.cst32." + SectionSuffix + ".",
                                  ELF::SHT_PROGBITS,
                                  ELF::SHF_ALLOC | ELF::SHF_MERGE, 32);
   if (Kind.isReadOnly())
-    return Context.getELFSection(".rodata." + SectionSuffix, ELF::SHT_PROGBITS,
-                                 ELF::SHF_ALLOC);
+    return Context.getELFSection(".rodata." + SectionSuffix + ".",
+                                 ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 
   assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
-  return Context.getELFSection(".data.rel.ro." + SectionSuffix,
+  return Context.getELFSection(".data.rel.ro." + SectionSuffix + ".",
                                ELF::SHT_PROGBITS,
                                ELF::SHF_ALLOC | ELF::SHF_WRITE);
 }
diff --git a/llvm/test/CodeGen/AArch64/constant-pool-partition.ll b/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
index d4447131e9de1..9f4b3e21f22b5 100644
--- a/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
+++ b/llvm/test/CodeGen/AArch64/constant-pool-partition.ll
@@ -19,11 +19,11 @@
 ;   function, constant pools for this constant should not have `.unlikely` suffix.
 
 ;; Constant pools for function @cold_func.
-; CHECK:       .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:       .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI0_0:
 ; CHECK-NEXT:	    .xword	0x3fe5c28f5c28f5c3              // double 0.68000000000000005
-; CHECK-NEXT: .section	.rodata.cst8.unlikely,"aM",@progbits,8
+; CHECK-NEXT: .section	.rodata.cst8.unlikely.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI0_1:
 ; CHECK-NEXT:     .xword 0x3fe5eb851eb851ec              // double 0.68500000000000005
@@ -58,7 +58,7 @@
 ; CHECK-NEXT:     .word 3                                 // 0x3
 ; CHECK-NEXT:     .word 5                                 // 0x5
 ; CHECK-NEXT:     .word 7                                 // 0x7
-; CHECK-NEXT: .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT: .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI1_2:
 ; CHECK-NEXT:     .word   442                             // 0x1ba
@@ -67,11 +67,11 @@
 ; CHECK-NEXT:     .word   0                               // 0x0
 
 ;; Constant pools for function @hot_func
-; CHECK:      .section        .rodata.cst8.hot,"aM",@progbits,8
+; CHECK:      .section        .rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI2_0:
 ; CHECK-NEXT:     .xword  0x3fe5c28f5c28f5c3              // double 0.68000000000000005
-; CHECK-NEXT: .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT: .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:     .p2align
 ; CHECK-NEXT:   .LCPI2_1:
 ; CHECK-NEXT:     .word   0                               // 0x0
diff --git a/llvm/test/CodeGen/X86/constant-pool-partition.ll b/llvm/test/CodeGen/X86/constant-pool-partition.ll
index 515284fb2cf1a..e42b41b257651 100644
--- a/llvm/test/CodeGen/X86/constant-pool-partition.ll
+++ b/llvm/test/CodeGen/X86/constant-pool-partition.ll
@@ -24,11 +24,11 @@ target triple = "x86_64-grtev4-linux-gnu"
 ; RUN:     %s -o - 2>&1 | FileCheck %s --dump-input=always
 
 ;; For function @cold_func
-; CHECK:       .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:       .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI0_0:
 ; CHECK-NEXT:	     .quad	0x3fe5c28f5c28f5c3              # double 0.68000000000000005
-; CHECK-NEXT:  .section	.rodata.cst8.unlikely,"aM",@progbits,8
+; CHECK-NEXT:  .section	.rodata.cst8.unlikely.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI0_1:
 ; CHECK-NEXT:	     .quad	0x3eb0000000000000              # double 9.5367431640625E-7
@@ -50,11 +50,11 @@ target triple = "x86_64-grtev4-linux-gnu"
 ; CHECK-NEXT:     .long   0x3e000000              # float 0.125
 
 ;; For function @hot_func
-; CHECK:	     .section	.rodata.cst8.hot,"aM",@progbits,8
+; CHECK:	     .section	.rodata.cst8.hot.,"aM",@progbits,8
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI3_0:
 ; CHECK-NEXT:     .quad	0x3fe5c28f5c28f5c3              # double 0.68000000000000005
-; CHECK-NEXT:  .section        .rodata.cst16.hot,"aM",@progbits,16
+; CHECK-NEXT:  .section        .rodata.cst16.hot.,"aM",@progbits,16
 ; CHECK-NEXT:      .p2align
 ; CHECK-NEXT:    .LCPI3_1:
 ; CHECK-NEXT:      .long   2147483648                      # 0x80000000

snehasish
snehasish approved these changes Jul 29, 2025
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lgtm

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thanks for the reviews!

@mingmingl-llvm mingmingl-llvm merged commit 277bcf7 into main Jul 30, 2025
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@mingmingl-llvm mingmingl-llvm deleted the users/mingmingl-llvm/constantpool branch July 30, 2025 00:05
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