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[X86] Treat __ehdr_start as large #79884

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Merged
merged 1 commit into from
Jan 29, 2024
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[X86] Treat __ehdr_start as large #79884

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2 changes: 2 additions & 0 deletions llvm/lib/Target/TargetMachine.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,8 @@ bool TargetMachine::isLargeGlobalValue(const GlobalValue *GVal) const {
getCodeModel() == CodeModel::Large) {
if (!GV->getValueType()->isSized())
return true;
if (GV->isDeclaration() && GV->getName() == "__ehdr_start")
return true;
const DataLayout &DL = GV->getParent()->getDataLayout();
uint64_t Size = DL.getTypeSizeInBits(GV->getValueType()) / 8;
return Size == 0 || Size > LargeDataThreshold;
Expand Down
130 changes: 94 additions & 36 deletions llvm/test/CodeGen/X86/code-model-elf.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ target triple = "x86_64--linux"
@opaque = external dso_local global %t
@forced_small_data = dso_local global [10 x i32] zeroinitializer, code_model "small", align 16
@forced_large_data = dso_local global [10 x i32] zeroinitializer, code_model "large", align 16
@__ehdr_start = external dso_local global i8
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Do users declare __ehdr_start as hidden in C source code? Is that why it is known to be DSO local? Otherwise, it's a declaration, so I would assume that you get the large access pattern by default.

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it can be declared with hidden visibility, e.g.

llvm-project/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c

Line 159 in e6fdbd1

extern const ElfW(Ehdr) __ehdr_start __attribute__((visibility("hidden")));

if the declaration type has a size, we respect the size of the type in regards to the large data threshold since we assume the definition has the same type

we have a similar issue with __start/__stop symbols declarations, will send out a patch for that soon


define dso_local ptr @lea_static_data() #0 {
; SMALL-STATIC-LABEL: lea_static_data:
Expand Down Expand Up @@ -800,6 +801,63 @@ define dso_local ptr @lea_opaque() #0 {
ret ptr @opaque
}

define dso_local ptr @lea_ehdr_start() #0 {
; SMALL-STATIC-LABEL: lea_ehdr_start:
; SMALL-STATIC: # %bb.0:
; SMALL-STATIC-NEXT: movl $__ehdr_start, %eax
; SMALL-STATIC-NEXT: retq
;
; MEDIUM-STATIC-LABEL: lea_ehdr_start:
; MEDIUM-STATIC: # %bb.0:
; MEDIUM-STATIC-NEXT: movabsq $__ehdr_start, %rax
; MEDIUM-STATIC-NEXT: retq
;
; LARGE-STATIC-LABEL: lea_ehdr_start:
; LARGE-STATIC: # %bb.0:
; LARGE-STATIC-NEXT: movabsq $__ehdr_start, %rax
; LARGE-STATIC-NEXT: retq
;
; SMALL-PIC-LABEL: lea_ehdr_start:
; SMALL-PIC: # %bb.0:
; SMALL-PIC-NEXT: leaq __ehdr_start(%rip), %rax
; SMALL-PIC-NEXT: retq
;
; MEDIUM-SMALL-DATA-PIC-LABEL: lea_ehdr_start:
; MEDIUM-SMALL-DATA-PIC: # %bb.0:
; MEDIUM-SMALL-DATA-PIC-NEXT: leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
; MEDIUM-SMALL-DATA-PIC-NEXT: movabsq $__ehdr_start@GOTOFF, %rax
; MEDIUM-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
; MEDIUM-SMALL-DATA-PIC-NEXT: retq
;
; MEDIUM-PIC-LABEL: lea_ehdr_start:
; MEDIUM-PIC: # %bb.0:
; MEDIUM-PIC-NEXT: leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
; MEDIUM-PIC-NEXT: movabsq $__ehdr_start@GOTOFF, %rax
; MEDIUM-PIC-NEXT: addq %rcx, %rax
; MEDIUM-PIC-NEXT: retq
;
; LARGE-PIC-LABEL: lea_ehdr_start:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L13$pb:
; LARGE-PIC-NEXT: leaq .L13$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L13$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $__ehdr_start@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_ehdr_start:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L13$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L13$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L13$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $__ehdr_start@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
; LARGE-SMALL-DATA-PIC-NEXT: retq
ret ptr @__ehdr_start
}

define dso_local void @global_fn() #0 {
; CHECK-LABEL: global_fn:
; CHECK: # %bb.0:
Expand Down Expand Up @@ -861,19 +919,19 @@ define dso_local ptr @lea_static_fn() #0 {
;
; LARGE-PIC-LABEL: lea_static_fn:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L16$pb:
; LARGE-PIC-NEXT: leaq .L16$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L16$pb, %rcx
; LARGE-PIC-NEXT: .L17$pb:
; LARGE-PIC-NEXT: leaq .L17$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L17$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $static_fn@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_static_fn:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L16$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L16$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L16$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L17$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L17$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L17$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $static_fn@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
Expand Down Expand Up @@ -914,19 +972,19 @@ define dso_local ptr @lea_global_fn() #0 {
;
; LARGE-PIC-LABEL: lea_global_fn:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L17$pb:
; LARGE-PIC-NEXT: leaq .L17$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L17$pb, %rcx
; LARGE-PIC-NEXT: .L18$pb:
; LARGE-PIC-NEXT: leaq .L18$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L18$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_fn@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_global_fn:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L17$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L17$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L17$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L18$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L18$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L18$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $global_fn@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
Expand Down Expand Up @@ -967,19 +1025,19 @@ define dso_local ptr @lea_extern_fn() #0 {
;
; LARGE-PIC-LABEL: lea_extern_fn:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L18$pb:
; LARGE-PIC-NEXT: leaq .L18$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L18$pb, %rcx
; LARGE-PIC-NEXT: .L19$pb:
; LARGE-PIC-NEXT: leaq .L19$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L19$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_fn@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_extern_fn:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L18$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L18$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L18$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L19$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L19$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L19$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $extern_fn@GOT, %rax
; LARGE-SMALL-DATA-PIC-NEXT: movq (%rcx,%rax), %rax
Expand Down Expand Up @@ -1020,19 +1078,19 @@ define dso_local ptr @lea_ifunc() #0 {
;
; LARGE-PIC-LABEL: lea_ifunc:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L19$pb:
; LARGE-PIC-NEXT: leaq .L19$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L19$pb, %rcx
; LARGE-PIC-NEXT: .L20$pb:
; LARGE-PIC-NEXT: leaq .L20$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L20$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $ifunc_func@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_ifunc:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L19$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L19$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L19$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L20$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L20$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L20$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $ifunc_func@GOT, %rax
; LARGE-SMALL-DATA-PIC-NEXT: movq (%rcx,%rax), %rax
Expand Down Expand Up @@ -1073,19 +1131,19 @@ define dso_local ptr @lea_dso_local_ifunc() #0 {
;
; LARGE-PIC-LABEL: lea_dso_local_ifunc:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L20$pb:
; LARGE-PIC-NEXT: leaq .L20$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L20$pb, %rcx
; LARGE-PIC-NEXT: .L21$pb:
; LARGE-PIC-NEXT: leaq .L21$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L21$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $dso_local_ifunc_func@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_dso_local_ifunc:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L20$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L20$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L20$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L21$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L21$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L21$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $dso_local_ifunc_func@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
Expand Down Expand Up @@ -1160,19 +1218,19 @@ define dso_local float @load_constant_pool(float %x) #0 {
;
; LARGE-PIC-LABEL: load_constant_pool:
; LARGE-PIC: # %bb.0:
; LARGE-PIC-NEXT: .L22$pb:
; LARGE-PIC-NEXT: leaq .L22$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L22$pb, %rcx
; LARGE-PIC-NEXT: .L23$pb:
; LARGE-PIC-NEXT: leaq .L23$pb(%rip), %rax
; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L23$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq ${{\.?LCPI[0-9]+_[0-9]+}}@GOTOFF, %rax
; LARGE-PIC-NEXT: addss (%rcx,%rax), %xmm0
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: load_constant_pool:
; LARGE-SMALL-DATA-PIC: # %bb.0:
; LARGE-SMALL-DATA-PIC-NEXT: .L22$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L22$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L22$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: .L23$pb:
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L23$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L23$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq ${{\.?LCPI[0-9]+_[0-9]+}}@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addss (%rcx,%rax), %xmm0
Expand Down