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[GlobalMerge]Prefer use global-merge-max-offset instead of the target-specific constant offset. #165591

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Merged
merged 4 commits into from
Nov 17, 2025
Merged

[GlobalMerge]Prefer use global-merge-max-offset instead of the target-specific constant offset. #165591

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dfe52c5
Prefer use global-merge-max-offset instead of the target-specific con…
hstk30-hw Oct 29, 2025
504be52
Update GlobalMerge.cpp
hstk30-hw Oct 30, 2025
52c5f5b
add test cases for ARM and AArch64
hstk30-hw Nov 15, 2025
8e68512
fix format and testcases
hstk30-hw Nov 16, 2025
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5 changes: 4 additions & 1 deletion llvm/lib/CodeGen/GlobalMerge.cpp
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Expand Up @@ -772,6 +772,9 @@ Pass *llvm::createGlobalMergePass(const TargetMachine *TM, unsigned Offset,
bool MergeConstAggressive = GlobalMergeAllConst.getNumOccurrences() > 0
? GlobalMergeAllConst
: MergeConstAggressiveByDefault;
return new GlobalMerge(TM, Offset, OnlyOptimizeForSize, MergeExternal,
unsigned PreferOffset = GlobalMergeMaxOffset.getNumOccurrences() > 0
? GlobalMergeMaxOffset
: Offset;
return new GlobalMerge(TM, PreferOffset, OnlyOptimizeForSize, MergeExternal,
MergeConstant, MergeConstAggressive);
}
19 changes: 12 additions & 7 deletions llvm/test/CodeGen/AArch64/global-merge.ll
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@@ -1,17 +1,22 @@
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O0 | FileCheck --check-prefix=NO-MERGE %s
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O1 | FileCheck --check-prefix=NO-MERGE %s
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O2 | FileCheck --check-prefix=NO-MERGE %s
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O3 | FileCheck %s
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O3 -global-merge-max-offset=0 | FileCheck %s --check-prefix=NO-MERGE
; RUN: llc < %s -mtriple=aarch64-none-linux-gnu -O0 -global-merge-on-external=true | FileCheck --check-prefix=NO-MERGE %s

; RUN: llc < %s -mtriple=aarch64-apple-ios -O0 | FileCheck %s --check-prefix=CHECK-APPLE-IOS-NO-MERGE
; RUN: llc < %s -mtriple=aarch64-apple-ios -O1 | FileCheck %s --check-prefix=CHECK-APPLE-IOS-NO-MERGE
; RUN: llc < %s -mtriple=aarch64-apple-ios -O2 | FileCheck %s --check-prefix=CHECK-APPLE-IOS-NO-MERGE
; RUN: llc < %s -mtriple=aarch64-apple-ios -O3 | FileCheck %s --check-prefix=CHECK-APPLE-IOS
; RUN: llc < %s -mtriple=aarch64-apple-ios -O0 -global-merge-on-external=true | FileCheck %s --check-prefix=CHECK-APPLE-IOS-NO-MERGE

; FIXME: add O1/O2 test for aarch64-none-linux-gnu and aarch64-apple-ios

@m = internal global i32 0, align 4
@n = internal global i32 0, align 4

define void @f1(i32 %a1, i32 %a2) {
; CHECK-LABEL: f1:
; CHECK: adrp x{{[0-9]+}}, _MergedGlobals
; CHECK: adrp x{{[0-9]+}}, .L_MergedGlobals
; CHECK-NOT: adrp

; CHECK-APPLE-IOS-LABEL: f1:
Expand All @@ -22,9 +27,9 @@ define void @f1(i32 %a1, i32 %a2) {
ret void
}

; CHECK: .local _MergedGlobals
; CHECK: .comm _MergedGlobals,8,8
; CHECK: .local .L_MergedGlobals
; CHECK: .comm .L_MergedGlobals,8,4
; NO-MERGE-NOT: .local _MergedGlobals

; CHECK-APPLE-IOS: .zerofill __DATA,__bss,__MergedGlobals,8,3
; CHECK-APPLE-IOS-NO-MERGE-NOT: .zerofill __DATA,__bss,__MergedGlobals,8,3
; CHECK-APPLE-IOS: .zerofill __DATA,__bss,__MergedGlobals,8,2
; CHECK-APPLE-IOS-NO-MERGE-NOT: .zerofill __DATA,__bss,__MergedGlobals,8,2
1 change: 1 addition & 0 deletions llvm/test/CodeGen/ARM/global-merge-1.ll
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Expand Up @@ -7,6 +7,7 @@
; RUN: llc %s -O3 -o - | FileCheck -check-prefix=MERGE %s
; RUN: llc %s -O3 -o - -arm-global-merge=false | FileCheck -check-prefix=NO-MERGE %s
; RUN: llc %s -O3 -o - -arm-global-merge=true | FileCheck -check-prefix=MERGE %s
; RUN: llc %s -O3 -o - -arm-global-merge=true -global-merge-max-offset=0 | FileCheck -check-prefix=NO-MERGE %s

; MERGE-NOT: .zerofill __DATA,__bss,_bar,20,2
; MERGE-NOT: .zerofill __DATA,__bss,_baz,20,2
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