[X86] Respect code models more when determining if a global reference can fit in 32 bits #75386
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@llvm/pr-subscribers-backend-x86 Author: Arthur Eubanks (aeubanks) ChangesFor non-GlobalValue references, the small and medium code models can use 32 bit constants. For GlobalValue references, use TargetMachine::isLargeGlobalObject(). Patch is 28.66 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/75386.diff 2 Files Affected:
diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index 545039b79f1616..363b6c7a4b4ab8 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -2940,15 +2940,18 @@ bool X86DAGToDAGISel::selectMOV64Imm32(SDValue N, SDValue &Imm) {
return false;
Imm = N;
- if (N->getOpcode() != ISD::TargetGlobalAddress)
- return TM.getCodeModel() == CodeModel::Small;
+ if (N->getOpcode() != ISD::TargetGlobalAddress) {
+ return TM.getCodeModel() == CodeModel::Small ||
+ TM.getCodeModel() == CodeModel::Medium;
+ }
- std::optional<ConstantRange> CR =
- cast<GlobalAddressSDNode>(N)->getGlobal()->getAbsoluteSymbolRange();
- if (!CR)
- return TM.getCodeModel() == CodeModel::Small;
+ const GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
+ if (std::optional<ConstantRange> CR = GV->getAbsoluteSymbolRange())
+ return CR->getUnsignedMax().ult(1ull << 32);
- return CR->getUnsignedMax().ult(1ull << 32);
+ if (auto *GO = GV->getAliaseeObject())
+ return !TM.isLargeGlobalObject(GO);
+ return true;
}
bool X86DAGToDAGISel::selectLEA64_32Addr(SDValue N, SDValue &Base,
diff --git a/llvm/test/CodeGen/X86/code-model-elf.ll b/llvm/test/CodeGen/X86/code-model-elf.ll
index 0f58ccaf298dab..a43736e2a5884a 100644
--- a/llvm/test/CodeGen/X86/code-model-elf.ll
+++ b/llvm/test/CodeGen/X86/code-model-elf.ll
@@ -40,6 +40,7 @@ target triple = "x86_64--linux"
@global_data = dso_local global [10 x i32] [i32 1, i32 2, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 0], align 16
@static_data = internal global [10 x i32] zeroinitializer, align 16
+@static_data_alias = internal constant ptr getelementptr inbounds ([10 x i32], ptr @static_data, i64 0, i64 2), align 8
@extern_data = external global [10 x i32], align 16
@thread_data = external thread_local global i32, align 4
@unknown_size_data = dso_local global [0 x i32] zeroinitializer, align 16
@@ -96,12 +97,67 @@ define dso_local ptr @lea_static_data() #0 {
; LARGE-SMALL-DATA-PIC-NEXT: leaq .L0$pb(%rip), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $static_data@GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $static_data@GOTOFF, %eax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
; LARGE-SMALL-DATA-PIC-NEXT: retq
ret ptr @static_data
}
+define dso_local ptr @lea_static_data_alias() #0 {
+; SMALL-STATIC-LABEL: lea_static_data_alias:
+; SMALL-STATIC: # %bb.0:
+; SMALL-STATIC-NEXT: movl $static_data_alias, %eax
+; SMALL-STATIC-NEXT: retq
+;
+; MEDIUM-STATIC-LABEL: lea_static_data_alias:
+; MEDIUM-STATIC: # %bb.0:
+; MEDIUM-STATIC-NEXT: movabsq $static_data_alias, %rax
+; MEDIUM-STATIC-NEXT: retq
+;
+; LARGE-STATIC-LABEL: lea_static_data_alias:
+; LARGE-STATIC: # %bb.0:
+; LARGE-STATIC-NEXT: movabsq $static_data_alias, %rax
+; LARGE-STATIC-NEXT: retq
+;
+; SMALL-PIC-LABEL: lea_static_data_alias:
+; SMALL-PIC: # %bb.0:
+; SMALL-PIC-NEXT: leaq static_data_alias(%rip), %rax
+; SMALL-PIC-NEXT: retq
+;
+; MEDIUM-SMALL-DATA-PIC-LABEL: lea_static_data_alias:
+; MEDIUM-SMALL-DATA-PIC: # %bb.0:
+; MEDIUM-SMALL-DATA-PIC-NEXT: leaq static_data_alias(%rip), %rax
+; MEDIUM-SMALL-DATA-PIC-NEXT: retq
+;
+; MEDIUM-PIC-LABEL: lea_static_data_alias:
+; MEDIUM-PIC: # %bb.0:
+; MEDIUM-PIC-NEXT: leaq _GLOBAL_OFFSET_TABLE_(%rip), %rcx
+; MEDIUM-PIC-NEXT: movabsq $static_data_alias@GOTOFF, %rax
+; MEDIUM-PIC-NEXT: addq %rcx, %rax
+; MEDIUM-PIC-NEXT: retq
+;
+; LARGE-PIC-LABEL: lea_static_data_alias:
+; LARGE-PIC: # %bb.0:
+; LARGE-PIC-NEXT: .L1$pb:
+; LARGE-PIC-NEXT: leaq .L1$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-PIC-NEXT: addq %rax, %rcx
+; LARGE-PIC-NEXT: movabsq $static_data_alias@GOTOFF, %rax
+; LARGE-PIC-NEXT: addq %rcx, %rax
+; LARGE-PIC-NEXT: retq
+;
+; LARGE-SMALL-DATA-PIC-LABEL: lea_static_data_alias:
+; LARGE-SMALL-DATA-PIC: # %bb.0:
+; LARGE-SMALL-DATA-PIC-NEXT: .L1$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L1$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: movl $static_data_alias@GOTOFF, %eax
+; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: retq
+ ret ptr @static_data_alias
+}
+
define dso_local ptr @lea_global_data() #0 {
; SMALL-STATIC-LABEL: lea_global_data:
; SMALL-STATIC: # %bb.0:
@@ -137,9 +193,9 @@ define dso_local ptr @lea_global_data() #0 {
;
; LARGE-PIC-LABEL: lea_global_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L1$pb:
-; LARGE-PIC-NEXT: leaq .L1$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-PIC-NEXT: .L2$pb:
+; LARGE-PIC-NEXT: leaq .L2$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -147,11 +203,11 @@ define dso_local ptr @lea_global_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_global_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L1$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L1$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L2$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L2$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $global_data@GOTOFF, %eax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
; LARGE-SMALL-DATA-PIC-NEXT: retq
ret ptr @global_data
@@ -190,9 +246,9 @@ define dso_local ptr @lea_extern_data() #0 {
;
; LARGE-PIC-LABEL: lea_extern_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L2$pb:
-; LARGE-PIC-NEXT: leaq .L2$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
+; LARGE-PIC-NEXT: .L3$pb:
+; LARGE-PIC-NEXT: leaq .L3$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_data@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
@@ -200,11 +256,11 @@ define dso_local ptr @lea_extern_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_extern_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L2$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L2$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L2$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L3$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L3$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $extern_data@GOT, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $extern_data@GOT, %eax
; LARGE-SMALL-DATA-PIC-NEXT: movq (%rcx,%rax), %rax
; LARGE-SMALL-DATA-PIC-NEXT: retq
ret ptr @extern_data
@@ -247,9 +303,9 @@ define dso_local ptr @lea_unknown_size_data() #0 {
;
; LARGE-PIC-LABEL: lea_unknown_size_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L3$pb:
-; LARGE-PIC-NEXT: leaq .L3$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
+; LARGE-PIC-NEXT: .L4$pb:
+; LARGE-PIC-NEXT: leaq .L4$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -257,9 +313,9 @@ define dso_local ptr @lea_unknown_size_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_unknown_size_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L3$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L3$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L3$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L4$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L4$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
@@ -267,7 +323,6 @@ define dso_local ptr @lea_unknown_size_data() #0 {
ret ptr @unknown_size_data
}
-; TODO: make nopic small and medium instruction sequence the same
define dso_local ptr @lea_forced_small_data() #0 {
; SMALL-STATIC-LABEL: lea_forced_small_data:
; SMALL-STATIC: # %bb.0:
@@ -276,12 +331,12 @@ define dso_local ptr @lea_forced_small_data() #0 {
;
; MEDIUM-STATIC-LABEL: lea_forced_small_data:
; MEDIUM-STATIC: # %bb.0:
-; MEDIUM-STATIC-NEXT: movabsq $forced_small_data, %rax
+; MEDIUM-STATIC-NEXT: movl $forced_small_data, %eax
; MEDIUM-STATIC-NEXT: retq
;
; LARGE-STATIC-LABEL: lea_forced_small_data:
; LARGE-STATIC: # %bb.0:
-; LARGE-STATIC-NEXT: movabsq $forced_small_data, %rax
+; LARGE-STATIC-NEXT: movl $forced_small_data, %eax
; LARGE-STATIC-NEXT: retq
;
; SMALL-PIC-LABEL: lea_forced_small_data:
@@ -301,21 +356,21 @@ define dso_local ptr @lea_forced_small_data() #0 {
;
; LARGE-PIC-LABEL: lea_forced_small_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L4$pb:
-; LARGE-PIC-NEXT: leaq .L4$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
+; LARGE-PIC-NEXT: .L5$pb:
+; LARGE-PIC-NEXT: leaq .L5$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
-; LARGE-PIC-NEXT: movabsq $forced_small_data@GOTOFF, %rax
+; LARGE-PIC-NEXT: movl $forced_small_data@GOTOFF, %eax
; LARGE-PIC-NEXT: addq %rcx, %rax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_forced_small_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L4$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L4$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L4$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L5$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L5$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $forced_small_data@GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $forced_small_data@GOTOFF, %eax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
; LARGE-SMALL-DATA-PIC-NEXT: retq
ret ptr @forced_small_data
@@ -330,13 +385,13 @@ define dso_local i32 @load_forced_small_data() #0 {
;
; MEDIUM-STATIC-LABEL: load_forced_small_data:
; MEDIUM-STATIC: # %bb.0:
-; MEDIUM-STATIC-NEXT: movabsq $forced_small_data, %rax
+; MEDIUM-STATIC-NEXT: movl $forced_small_data, %eax
; MEDIUM-STATIC-NEXT: movl 8(%rax), %eax
; MEDIUM-STATIC-NEXT: retq
;
; LARGE-STATIC-LABEL: load_forced_small_data:
; LARGE-STATIC: # %bb.0:
-; LARGE-STATIC-NEXT: movabsq $forced_small_data, %rax
+; LARGE-STATIC-NEXT: movl $forced_small_data, %eax
; LARGE-STATIC-NEXT: movl 8(%rax), %eax
; LARGE-STATIC-NEXT: retq
;
@@ -359,21 +414,21 @@ define dso_local i32 @load_forced_small_data() #0 {
;
; LARGE-PIC-LABEL: load_forced_small_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L5$pb:
-; LARGE-PIC-NEXT: leaq .L5$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
+; LARGE-PIC-NEXT: .L6$pb:
+; LARGE-PIC-NEXT: leaq .L6$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
-; LARGE-PIC-NEXT: movabsq $forced_small_data@GOTOFF, %rax
+; LARGE-PIC-NEXT: movl $forced_small_data@GOTOFF, %eax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
; LARGE-PIC-NEXT: retq
;
; LARGE-SMALL-DATA-PIC-LABEL: load_forced_small_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L5$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L5$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L5$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L6$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L6$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $forced_small_data@GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $forced_small_data@GOTOFF, %eax
; LARGE-SMALL-DATA-PIC-NEXT: movl 8(%rcx,%rax), %eax
; LARGE-SMALL-DATA-PIC-NEXT: retq
%rv = load i32, ptr getelementptr inbounds (i32, ptr @forced_small_data, i64 2)
@@ -384,7 +439,7 @@ define dso_local i32 @load_forced_small_data() #0 {
define dso_local ptr @lea_forced_large_data() #0 {
; SMALL-STATIC-LABEL: lea_forced_large_data:
; SMALL-STATIC: # %bb.0:
-; SMALL-STATIC-NEXT: movl $forced_large_data, %eax
+; SMALL-STATIC-NEXT: movabsq $forced_large_data, %rax
; SMALL-STATIC-NEXT: retq
;
; MEDIUM-STATIC-LABEL: lea_forced_large_data:
@@ -419,9 +474,9 @@ define dso_local ptr @lea_forced_large_data() #0 {
;
; LARGE-PIC-LABEL: lea_forced_large_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L6$pb:
-; LARGE-PIC-NEXT: leaq .L6$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
+; LARGE-PIC-NEXT: .L7$pb:
+; LARGE-PIC-NEXT: leaq .L7$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L7$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $forced_large_data@GOTOFF, %rax
; LARGE-PIC-NEXT: addq %rcx, %rax
@@ -429,9 +484,9 @@ define dso_local ptr @lea_forced_large_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: lea_forced_large_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L6$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L6$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L6$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L7$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L7$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L7$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $forced_large_data@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: addq %rcx, %rax
@@ -479,9 +534,9 @@ define dso_local i32 @load_forced_large_data() #0 {
;
; LARGE-PIC-LABEL: load_forced_large_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L7$pb:
-; LARGE-PIC-NEXT: leaq .L7$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L7$pb, %rcx
+; LARGE-PIC-NEXT: .L8$pb:
+; LARGE-PIC-NEXT: leaq .L8$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L8$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $forced_large_data@GOTOFF, %rax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -489,9 +544,9 @@ define dso_local i32 @load_forced_large_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: load_forced_large_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L7$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L7$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L7$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L8$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L8$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L8$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $forced_large_data@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -538,9 +593,9 @@ define dso_local i32 @load_global_data() #0 {
;
; LARGE-PIC-LABEL: load_global_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L8$pb:
-; LARGE-PIC-NEXT: leaq .L8$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L8$pb, %rcx
+; LARGE-PIC-NEXT: .L9$pb:
+; LARGE-PIC-NEXT: leaq .L9$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L9$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -548,11 +603,11 @@ define dso_local i32 @load_global_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: load_global_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L8$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L8$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L8$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L9$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L9$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L9$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $global_data@GOTOFF, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $global_data@GOTOFF, %eax
; LARGE-SMALL-DATA-PIC-NEXT: movl 8(%rcx,%rax), %eax
; LARGE-SMALL-DATA-PIC-NEXT: retq
%rv = load i32, ptr getelementptr inbounds ([10 x i32], ptr @global_data, i64 0, i64 2)
@@ -598,9 +653,9 @@ define dso_local i32 @load_extern_data() #0 {
;
; LARGE-PIC-LABEL: load_extern_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L9$pb:
-; LARGE-PIC-NEXT: leaq .L9$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L9$pb, %rcx
+; LARGE-PIC-NEXT: .L10$pb:
+; LARGE-PIC-NEXT: leaq .L10$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $extern_data@GOT, %rax
; LARGE-PIC-NEXT: movq (%rcx,%rax), %rax
@@ -609,11 +664,11 @@ define dso_local i32 @load_extern_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: load_extern_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L9$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L9$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L9$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L10$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L10$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $extern_data@GOT, %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movl $extern_data@GOT, %eax
; LARGE-SMALL-DATA-PIC-NEXT: movq (%rcx,%rax), %rax
; LARGE-SMALL-DATA-PIC-NEXT: movl 8(%rax), %eax
; LARGE-SMALL-DATA-PIC-NEXT: retq
@@ -660,9 +715,9 @@ define dso_local i32 @load_unknown_size_data() #0 {
;
; LARGE-PIC-LABEL: load_unknown_size_data:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L10$pb:
-; LARGE-PIC-NEXT: leaq .L10$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
+; LARGE-PIC-NEXT: .L11$pb:
+; LARGE-PIC-NEXT: leaq .L11$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L11$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -670,9 +725,9 @@ define dso_local i32 @load_unknown_size_data() #0 {
;
; LARGE-SMALL-DATA-PIC-LABEL: load_unknown_size_data:
; LARGE-SMALL-DATA-PIC: # %bb.0:
-; LARGE-SMALL-DATA-PIC-NEXT: .L10$pb:
-; LARGE-SMALL-DATA-PIC-NEXT: leaq .L10$pb(%rip), %rax
-; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L10$pb, %rcx
+; LARGE-SMALL-DATA-PIC-NEXT: .L11$pb:
+; LARGE-SMALL-DATA-PIC-NEXT: leaq .L11$pb(%rip), %rax
+; LARGE-SMALL-DATA-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L11$pb, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: addq %rax, %rcx
; LARGE-SMALL-DATA-PIC-NEXT: movabsq $unknown_size_data@GOTOFF, %rax
; LARGE-SMALL-DATA-PIC-NEXT: movl 8(%rcx,%rax), %eax
@@ -718,9 +773,9 @@ define dso_local ptr @lea_opaque() #0 {
;
; LARGE-PIC-LABEL: lea_opaque:
; LARGE-PIC: # %bb.0:
-; LARGE-PIC-NEXT: .L11$pb:
-; LARGE-PIC-NEXT: leaq .L11$pb(%rip), %rax
-; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L11$pb, %rcx
+; LARGE-PIC-NEXT: .L12$pb:
+; LARGE-PIC-NEXT: leaq .L12$pb(%rip), %rax
+; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L12$pb, %rcx
; LARGE-PIC-NEXT: addq %rax, %rcx
; LARGE-PIC-NEXT: mo...
[truncated]
|
… can fit in 32 bits For non-GlobalValue references, the small and medium code models can use 32 bit constants. For GlobalValue references, use TargetMachine::isLargeGlobalObject(). Look through aliases for determining if a GlobalValue is small or large.
…lowup changes want to do similar checks
rnk
reviewed
Dec 14, 2023
| @@ -91,9 +91,8 @@ X86Subtarget::classifyLocalReference(const GlobalValue *GV) const { | |||
| if (CM == CodeModel::Large) | |||
There was a problem hiding this comment.
Is this condition correct? It seems like it won't handle globals explicitly marked with code_model "small" correctly.
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Even a small global in the large code model cannot be referenced rip-relatively since ltext is far from all data. So it needs to use GOTOFF, whether that's a 32-bit (for small data) or 64-bit (for large data) GOTOFF.
llvm/lib/Target/X86/X86Subtarget.cpp
Outdated
| return TM.isLargeGlobalObject(GO) ? X86II::MO_GOTOFF | ||
| : X86II::MO_NO_FLAG; | ||
| if (GV) | ||
| return TM.isLargeGlobalValue(GV) ? X86II::MO_GOTOFF : X86II::MO_NO_FLAG; | ||
| // For non-GlobalObjects, the small and medium code models treat them as |
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This comment seems stale. What does it mean if GV is null? Does that represent a reference to a local label, something like a constant pool?
| ; LARGE-PIC: # %bb.0: | ||
| ; LARGE-PIC-NEXT: .L1$pb: | ||
| ; LARGE-PIC-NEXT: leaq .L1$pb(%rip), %rax | ||
| ; LARGE-PIC-NEXT: movabsq $_GLOBAL_OFFSET_TABLE_-.L1$pb, %rcx |
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The large PIC code model is awful. Is there really no way to express $static_data_alias - .L1$pb with a static relocation? That would avoid the need for the second add and i64 materialization.
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the problem is relocations only allow one symbol to relocate against, we can't just diff two symbols. so we have to take advantage of the other implicit operands in the relocations, e.g. the PC/GOT/PLT, for PIC. for example, using the GOT as an anchor requires a 64-bit relocation to get the address of the GOT. the only anchor that x86-64 static relocations provide that can be assumed to be close to the instruction is the PC, so we'd probably need to use R_X86_64_PC64 (seems like this is a rare relocation type). perhaps something like the following
leaq .L(%rip), %rax
.L
movabsq foo-%rip, %rbx
addq %rbx, %rax
but now you need a label for every reference to a global. I'm not sure how much this impacts optimizations. (do optimizations take care to not move around labels if their relative placement with instructions matter?)
maybe this is worth experimenting with at some point
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Makes sense. I suppose the GOT materialization only happens once per function anyway, so each symbol reference really only requires one movabsq & add. So, it's not really worth further exploration.
| @@ -1072,7 +1127,7 @@ define dso_local float @load_constant_pool(float %x) #0 { | |||
| ; | |||
| ; MEDIUM-STATIC-LABEL: load_constant_pool: | |||
| ; MEDIUM-STATIC: # %bb.0: | |||
| ; MEDIUM-STATIC-NEXT: movabsq ${{\.?LCPI[0-9]+_[0-9]+}}, %rax | |||
| ; MEDIUM-STATIC-NEXT: movl ${{\.?LCPI[0-9]+_[0-9]+}}, %eax | |||
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These constant pool changes look correct.
|
aeubanks
added a commit
that referenced
this pull request
Dec 14, 2023
…ference can fit in 32 bits (#75386) For non-GlobalValue references, the small and medium code models can use 32 bit constants. For GlobalValue references, use TargetMachine::isLargeGlobalObject(). Look through aliases for determining if a GlobalValue is small or large. Even the large code model can reference small objects with 32 bit constants as long as we're in no-pic mode, or if the reference is offset from the GOT. Original commit broke the build...
|
+1 We're also seeing this failure in our internal CI. |
aeubanks
added a commit
that referenced
this pull request
Dec 14, 2023
…lobal reference can fit in 32 bits (#75386)" This reverts commit ec92d74. Breaks some compiler-rt tests, e.g. https://lab.llvm.org/buildbot/#/builders/37/builds/28834
|
reverted, taking a look |
aeubanks
added a commit
that referenced
this pull request
Dec 14, 2023
… reference can fit in 32 bits (#75386) For non-GlobalValue references, the small and medium code models can use 32 bit constants. For GlobalValue references, use TargetMachine::isLargeGlobalObject(). Look through aliases for determining if a GlobalValue is small or large. Even the large code model can reference small objects with 32 bit constants as long as we're in no-pic mode, or if the reference is offset from the GOT. Original commit broke the build... First reland broke large PIC builds referencing small data since it was using GOTOFF as a 32-bit constant.
qihangkong
pushed a commit
to rvgpu/rvgpu-llvm
that referenced
this pull request
Apr 23, 2024
…eference can fit in 32 bits" (#75500) Reverts llvm/llvm-project#75386 Breaks build.
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For non-GlobalValue references, the small and medium code models can use 32 bit constants.
For GlobalValue references, use TargetMachine::isLargeGlobalObject().
Look through aliases for determining if a GlobalValue is small or large.
Even the large code model can reference small objects with 32 bit constants as long as we're in no-pic mode, or if the reference is offset from the GOT.