[ELF] Fix large code model MIR verifier errors

Instead of using the MOVGOT64r pseudo, use the existing
MO_PIC_BASE_OFFSET support on symbol operands. Now I don't have to
create a "scratch register operand" for the pseudo to use, and the
register allocator can make better decisions.

Fixes some X86 verifier errors tracked in PR27481.

llvm-svn: 345219

6 files changed, 78 insertions, 102 deletions

diff --git a/llvm/lib/Target/X86/X86InstrCompiler.td b/llvm/lib/Target/X86/X86InstrCompiler.td
index 11d6edd55d4..2805517b747 100644
--- a/llvm/lib/Target/X86/X86InstrCompiler.td
+++ b/llvm/lib/Target/X86/X86InstrCompiler.td
@@ -37,11 +37,6 @@ let hasSideEffects = 0, isNotDuplicable = 1, Uses = [ESP, SSP],
   def MOVPC32r : Ii32<0xE8, Pseudo, (outs GR32:$reg), (ins i32imm:$label),
                       "", []>;
 
-// 64-bit large code model PIC base construction.
-let hasSideEffects = 0, mayLoad = 1, isNotDuplicable = 1, SchedRW = [WriteJump] in
-  def MOVGOT64r : PseudoI<(outs GR64:$reg),
-                          (ins GR64:$scratch, i64i32imm_pcrel:$got), []>;
-
 // ADJCALLSTACKDOWN/UP implicitly use/def ESP because they may be expanded into
 // a stack adjustment and the codegen must know that they may modify the stack
 // pointer before prolog-epilog rewriting occurs.
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index e62c8403693..db0cb63ae69 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -7488,12 +7488,28 @@ namespace {
               .addExternalSymbol("_GLOBAL_OFFSET_TABLE_")
               .addReg(0);
         } else if (TM->getCodeModel() == CodeModel::Large) {
-          // Loading the GOT in the large code model requires math with labels,
-          // so we use a pseudo instruction and expand it during MC emission.
-          unsigned Scratch = RegInfo.createVirtualRegister(&X86::GR64RegClass);
-          BuildMI(FirstMBB, MBBI, DL, TII->get(X86::MOVGOT64r), PC)
-              .addReg(Scratch, RegState::Undef | RegState::Define)
-              .addExternalSymbol("_GLOBAL_OFFSET_TABLE_");
+          // In the large code model, we are aiming for this code, though the
+          // register allocation may vary:
+          //   leaq .LN$pb(%rip), %rax
+          //   movq $_GLOBAL_OFFSET_TABLE_ - .LN$pb, %rcx
+          //   addq %rcx, %rax
+          // RAX now holds address of _GLOBAL_OFFSET_TABLE_.
+          unsigned PBReg = RegInfo.createVirtualRegister(&X86::GR64RegClass);
+          unsigned GOTReg =
+              RegInfo.createVirtualRegister(&X86::GR64RegClass);
+          BuildMI(FirstMBB, MBBI, DL, TII->get(X86::LEA64r), PBReg)
+              .addReg(X86::RIP)
+              .addImm(0)
+              .addReg(0)
+              .addSym(MF.getPICBaseSymbol())
+              .addReg(0);
+          std::prev(MBBI)->setPreInstrSymbol(MF, MF.getPICBaseSymbol());
+          BuildMI(FirstMBB, MBBI, DL, TII->get(X86::MOV64ri), GOTReg)
+              .addExternalSymbol("_GLOBAL_OFFSET_TABLE_",
+                                 X86II::MO_PIC_BASE_OFFSET);
+          BuildMI(FirstMBB, MBBI, DL, TII->get(X86::ADD64rr), PC)
+              .addReg(PBReg, RegState::Kill)
+              .addReg(GOTReg, RegState::Kill);
         } else {
           llvm_unreachable("unexpected code model");
         }
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 74fe85851cb..86495f16c3a 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -1709,41 +1709,6 @@ void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
     return;
   }
 
-  case X86::MOVGOT64r: {
-    // Materializes the GOT for the 64-bit large code model.
-    MCSymbol *DotSym = OutContext.createTempSymbol();
-    OutStreamer->EmitLabel(DotSym);
-
-    unsigned DstReg = MI->getOperand(0).getReg();
-    unsigned ScratchReg = MI->getOperand(1).getReg();
-    MCSymbol *GOTSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2));
-
-    // .LtmpN: leaq .LtmpN(%rip), %dst
-    const MCExpr *DotExpr = MCSymbolRefExpr::create(DotSym, OutContext);
-    EmitAndCountInstruction(MCInstBuilder(X86::LEA64r)
-                                .addReg(DstReg)   // dest
-                                .addReg(X86::RIP) // base
-                                .addImm(1)        // scale
-                                .addReg(0)        // index
-                                .addExpr(DotExpr) // disp
-                                .addReg(0));      // seg
-
-    // movq $_GLOBAL_OFFSET_TABLE_ - .LtmpN, %scratch
-    const MCExpr *GOTSymExpr = MCSymbolRefExpr::create(GOTSym, OutContext);
-    const MCExpr *GOTDiffExpr =
-        MCBinaryExpr::createSub(GOTSymExpr, DotExpr, OutContext);
-    EmitAndCountInstruction(MCInstBuilder(X86::MOV64ri)
-                                .addReg(ScratchReg)     // dest
-                                .addExpr(GOTDiffExpr)); // disp
-
-    // addq %scratch, %dst
-    EmitAndCountInstruction(MCInstBuilder(X86::ADD64rr)
-                                .addReg(DstReg)       // dest
-                                .addReg(DstReg)       // dest
-                                .addReg(ScratchReg)); // src
-    return;
-  }
-
   case X86::ADD32ri: {
     // Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri.
     if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS)
diff --git a/llvm/test/CodeGen/X86/code-model-elf-memset.ll b/llvm/test/CodeGen/X86/code-model-elf-memset.ll
index ba34aaeddcb..2f429f32eab 100644
--- a/llvm/test/CodeGen/X86/code-model-elf-memset.ll
+++ b/llvm/test/CodeGen/X86/code-model-elf-memset.ll
@@ -56,16 +56,16 @@ define i32 @main() #0 {
 ; LARGE-PIC:       # %bb.0: # %entry
 ; LARGE-PIC-NEXT:    subq $424, %rsp # imm = 0x1A8
 ; LARGE-PIC-NEXT:    .cfi_def_cfa_offset 432
-; LARGE-PIC-NEXT:  .Ltmp0:
-; LARGE-PIC-NEXT:    leaq {{.*}}(%rip), %rax
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp0, %rcx
-; LARGE-PIC-NEXT:    addq %rcx, %rax
+; LARGE-PIC-NEXT:  .L0$pb:
+; LARGE-PIC-NEXT:    leaq .L0$pb(%rip), %rax
+; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
+; LARGE-PIC-NEXT:    addq %rax, %rcx
 ; LARGE-PIC-NEXT:    movl $0, {{[0-9]+}}(%rsp)
 ; LARGE-PIC-NEXT:    leaq {{[0-9]+}}(%rsp), %rdi
-; LARGE-PIC-NEXT:    movabsq $memset@GOT, %rcx
+; LARGE-PIC-NEXT:    movabsq $memset@GOT, %rax
 ; LARGE-PIC-NEXT:    xorl %esi, %esi
 ; LARGE-PIC-NEXT:    movl $400, %edx # imm = 0x190
-; LARGE-PIC-NEXT:    callq *(%rax,%rcx)
+; LARGE-PIC-NEXT:    callq *(%rcx,%rax)
 ; LARGE-PIC-NEXT:    xorl %eax, %eax
 ; LARGE-PIC-NEXT:    addq $424, %rsp # imm = 0x1A8
 ; LARGE-PIC-NEXT:    .cfi_def_cfa_offset 8
diff --git a/llvm/test/CodeGen/X86/code-model-elf.ll b/llvm/test/CodeGen/X86/code-model-elf.ll
index 6d62f256179..56d3f4c102f 100644
--- a/llvm/test/CodeGen/X86/code-model-elf.ll
+++ b/llvm/test/CodeGen/X86/code-model-elf.ll
@@ -2,12 +2,12 @@
 ; Run with --no_x86_scrub_rip because we care a lot about how globals are
 ; accessed in the code model.
 
-; RUN: llc < %s -relocation-model=static -code-model=small  | FileCheck %s --check-prefix=CHECK --check-prefix=SMALL-STATIC
-; RUN: llc < %s -relocation-model=static -code-model=medium | FileCheck %s --check-prefix=CHECK --check-prefix=MEDIUM-STATIC
-; RUN: llc < %s -relocation-model=static -code-model=large  | FileCheck %s --check-prefix=CHECK --check-prefix=LARGE-STATIC
-; RUN: llc < %s -relocation-model=pic    -code-model=small  | FileCheck %s --check-prefix=CHECK --check-prefix=SMALL-PIC
-; RUN: llc < %s -relocation-model=pic    -code-model=medium | FileCheck %s --check-prefix=CHECK --check-prefix=MEDIUM-PIC
-; RUN: llc < %s -relocation-model=pic    -code-model=large  | FileCheck %s --check-prefix=CHECK --check-prefix=LARGE-PIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=static -code-model=small  | FileCheck %s --check-prefix=CHECK --check-prefix=SMALL-STATIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=static -code-model=medium | FileCheck %s --check-prefix=CHECK --check-prefix=MEDIUM-STATIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=static -code-model=large  | FileCheck %s --check-prefix=CHECK --check-prefix=LARGE-STATIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=pic    -code-model=small  | FileCheck %s --check-prefix=CHECK --check-prefix=SMALL-PIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=pic    -code-model=medium | FileCheck %s --check-prefix=CHECK --check-prefix=MEDIUM-PIC
+; RUN: llc -verify-machineinstrs < %s -relocation-model=pic    -code-model=large  | FileCheck %s --check-prefix=CHECK --check-prefix=LARGE-PIC
 
 ; Generated from this C source:
 ;
@@ -68,9 +68,9 @@ define dso_local i32* @lea_static_data() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_static_data:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp0:
-; LARGE-PIC-NEXT:    leaq .Ltmp0(%rip), %rcx
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp0, %rax
+; LARGE-PIC-NEXT:  .L0$pb:
+; LARGE-PIC-NEXT:    leaq .L0$pb(%rip), %rax
+; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
 ; LARGE-PIC-NEXT:    addq %rax, %rcx
 ; LARGE-PIC-NEXT:    movabsq $static_data@GOTOFF, %rax
 ; LARGE-PIC-NEXT:    addq %rcx, %rax
@@ -108,9 +108,9 @@ define dso_local i32* @lea_global_data() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_global_data:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp1:
-; LARGE-PIC-NEXT:    leaq .Ltmp1(%rip), %rcx
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp1, %rax
+; LARGE-PIC-NEXT:  .L1$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 $global_data@GOTOFF, %rax
 ; LARGE-PIC-NEXT:    addq %rcx, %rax
@@ -146,12 +146,12 @@ define dso_local i32* @lea_extern_data() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_extern_data:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp2:
-; LARGE-PIC-NEXT:    leaq .Ltmp2(%rip), %rax
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp2, %rcx
-; LARGE-PIC-NEXT:    addq %rcx, %rax
-; LARGE-PIC-NEXT:    movabsq $extern_data@GOT, %rcx
-; LARGE-PIC-NEXT:    movq (%rax,%rcx), %rax
+; LARGE-PIC-NEXT:  .L2$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 $extern_data@GOT, %rax
+; LARGE-PIC-NEXT:    movq (%rcx,%rax), %rax
 ; LARGE-PIC-NEXT:    retq
   ret i32* getelementptr inbounds ([10 x i32], [10 x i32]* @extern_data, i64 0, i64 0)
 }
@@ -188,12 +188,12 @@ define dso_local i32 @load_global_data() #0 {
 ;
 ; LARGE-PIC-LABEL: load_global_data:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp3:
-; LARGE-PIC-NEXT:    leaq .Ltmp3(%rip), %rax
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp3, %rcx
-; LARGE-PIC-NEXT:    addq %rcx, %rax
-; LARGE-PIC-NEXT:    movabsq $global_data@GOTOFF, %rcx
-; LARGE-PIC-NEXT:    movl 8(%rax,%rcx), %eax
+; LARGE-PIC-NEXT:  .L3$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 $global_data@GOTOFF, %rax
+; LARGE-PIC-NEXT:    movl 8(%rcx,%rax), %eax
 ; LARGE-PIC-NEXT:    retq
   %rv = load i32, i32* getelementptr inbounds ([10 x i32], [10 x i32]* @global_data, i64 0, i64 2)
   ret i32 %rv
@@ -231,12 +231,12 @@ define dso_local i32 @load_extern_data() #0 {
 ;
 ; LARGE-PIC-LABEL: load_extern_data:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp4:
-; LARGE-PIC-NEXT:    leaq .Ltmp4(%rip), %rax
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp4, %rcx
-; LARGE-PIC-NEXT:    addq %rcx, %rax
-; LARGE-PIC-NEXT:    movabsq $extern_data@GOT, %rcx
-; LARGE-PIC-NEXT:    movq (%rax,%rcx), %rax
+; LARGE-PIC-NEXT:  .L4$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 $extern_data@GOT, %rax
+; LARGE-PIC-NEXT:    movq (%rcx,%rax), %rax
 ; LARGE-PIC-NEXT:    movl 8(%rax), %eax
 ; LARGE-PIC-NEXT:    retq
   %rv = load i32, i32* getelementptr inbounds ([10 x i32], [10 x i32]* @extern_data, i64 0, i64 2)
@@ -287,9 +287,9 @@ define dso_local void ()* @lea_static_fn() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_static_fn:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp5:
-; LARGE-PIC-NEXT:    leaq .Ltmp5(%rip), %rcx
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp5, %rax
+; LARGE-PIC-NEXT:  .L7$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 $static_fn@GOTOFF, %rax
 ; LARGE-PIC-NEXT:    addq %rcx, %rax
@@ -325,9 +325,9 @@ define dso_local void ()* @lea_global_fn() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_global_fn:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp6:
-; LARGE-PIC-NEXT:    leaq .Ltmp6(%rip), %rcx
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp6, %rax
+; LARGE-PIC-NEXT:  .L8$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 $global_fn@GOTOFF, %rax
 ; LARGE-PIC-NEXT:    addq %rcx, %rax
@@ -363,12 +363,12 @@ define dso_local void ()* @lea_extern_fn() #0 {
 ;
 ; LARGE-PIC-LABEL: lea_extern_fn:
 ; LARGE-PIC:       # %bb.0:
-; LARGE-PIC-NEXT:  .Ltmp7:
-; LARGE-PIC-NEXT:    leaq .Ltmp7(%rip), %rax
-; LARGE-PIC-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp7, %rcx
-; LARGE-PIC-NEXT:    addq %rcx, %rax
-; LARGE-PIC-NEXT:    movabsq $extern_fn@GOT, %rcx
-; LARGE-PIC-NEXT:    movq (%rax,%rcx), %rax
+; LARGE-PIC-NEXT:  .L9$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 $extern_fn@GOT, %rax
+; LARGE-PIC-NEXT:    movq (%rcx,%rax), %rax
 ; LARGE-PIC-NEXT:    retq
   ret void ()* @extern_fn
 }
diff --git a/llvm/test/CodeGen/X86/large-pic-string.ll b/llvm/test/CodeGen/X86/large-pic-string.ll
index be8a629c31c..e677ed85c66 100644
--- a/llvm/test/CodeGen/X86/large-pic-string.ll
+++ b/llvm/test/CodeGen/X86/large-pic-string.ll
@@ -1,19 +1,19 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 
-; RUN: llc < %s -code-model=large -relocation-model=pic -mtriple=x86_64--linux | FileCheck %s
+; RUN: llc -verify-machineinstrs < %s -code-model=large -relocation-model=pic -mtriple=x86_64--linux | FileCheck %s
 
 @.str = private unnamed_addr constant [2 x i8] c"a\00", align 1
 
 define void @pr38385() {
 ; CHECK-LABEL: pr38385:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:  .Ltmp0:
-; CHECK-NEXT:    leaq {{.*}}(%rip), %rax
-; CHECK-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.Ltmp0, %rcx
-; CHECK-NEXT:    addq %rcx, %rax
-; CHECK-NEXT:    movabsq $.L.str@GOTOFF, %rcx
-; CHECK-NEXT:    addl %ecx, %eax
-; CHECK-NEXT:    movb %al, -{{[0-9]+}}(%rsp)
+; CHECK-NEXT:  .L0$pb:
+; CHECK-NEXT:    leaq .L0${{.*}}(%rip), %rax
+; CHECK-NEXT:    movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
+; CHECK-NEXT:    addq %rax, %rcx
+; CHECK-NEXT:    movabsq $.L.str@GOTOFF, %rax
+; CHECK-NEXT:    addl %eax, %ecx
+; CHECK-NEXT:    movb %cl, -{{[0-9]+}}(%rsp)
 ; CHECK-NEXT:    retq
   %p = alloca i8, align 1
   store i8 ptrtoint ([2 x i8]* @.str to i8), i8* %p, align 1