[X86] Fix position-independent TType encoding

[hvdijk]

Summary

The logic for x86_64 position-independent TType encodings was backwards, using 8 bytes where 4 were wanted and 4 where 8 were wanted. For regular x86_64, this was mostly harmless, exception tables are allowed to use 8-byte encodings even when it is not needed. For the large code model, and for X32, however, the generated exception tables were wrong. For the large code model, we cannot assume that the offset will fit in 4 bytes. For X32, we cannot use 64-bit relocations.

Fixes PR50148.

[RKSimon]

llvm/test/CodeGen/X86/gcc_except_table_bb_sections.ll

6

Add gnux32 specific triple tests?

[hvdijk]

Added gnux32 to test.

[hvdijk]

llvm/test/CodeGen/X86/gcc_except_table_bb_sections.ll

6

I was hoping to avoid it because the --check-prefixes are getting quite long and the change was already being tested without it, but alright, done.

[RKSimon]

LGTM

[MaskRay]

Thanks for fixing this:)

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

if (isPositionIndependent()) {
       PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         ((CM == CodeModel::Small || CM == CodeModel::Medium)
          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
       LSDAEncoding = dwarf::DW_EH_PE_pcrel |
         (CM == CodeModel::Small
          ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
       TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
         ((CM == CodeModel::Small || CM == CodeModel::Medium)
-         ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
+         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
     } else {
       PersonalityEncoding =
         (CM == CodeModel::Small || CM == CodeModel::Medium)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
       LSDAEncoding = (CM == CodeModel::Small)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
       TTypeEncoding = (CM == CodeModel::Small)
         ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;

llvm/test/CodeGen/X86/gcc_except_table_bb_sections.ll

-; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu < %s | FileCheck %s --check-prefixes=CHECK,CHECK-NON-PIC
-; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -relocation-model=pic < %s | FileCheck %s --check-prefixes=CHECK,CHECK-PIC
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -code-model=small < %s | FileCheck %s --check-prefixes=CHECK,CHECK-SMALL,CHECK-NON-PIC,CHECK-NON-PIC-SMALL,CHECK-NON-PIC-X64
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnux32 -code-model=small < %s | FileCheck %s --check-prefixes=CHECK,CHECK-SMALL,CHECK-NON-PIC,CHECK-NON-PIC-SMALL,CHECK-NON-PIC-X32
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -code-model=medium < %s | FileCheck %s --check-prefixes=CHECK,CHECK-MEDIUM,CHECK-NON-PIC,CHECK-NON-PIC-MEDIUM,CHECK-NON-PIC-X64
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -code-model=large < %s | FileCheck %s --check-prefixes=CHECK,CHECK-NON-PIC,CHECK-NON-PIC-LARGE,CHECK-NON-PIC-X64
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -relocation-model=pic -code-model=small < %s | FileCheck %s --check-prefixes=CHECK,CHECK-SMALL,CHECK-PIC,CHECK-PIC-SMALL,CHECK-PIC-X64
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnux32 -relocation-model=pic -code-model=small < %s | FileCheck %s --check-prefixes=CHECK,CHECK-SMALL,CHECK-PIC,CHECK-PIC-SMALL,CHECK-PIC-X32
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -relocation-model=pic -code-model=medium < %s | FileCheck %s --check-prefixes=CHECK,CHECK-MEDIUM,CHECK-PIC,CHECK-PIC-MEDIUM,CHECK-PIC-X64
+; RUN: llc -basic-block-sections=all -mtriple x86_64-pc-linux-gnu -relocation-model=pic -code-model=large < %s | FileCheck %s --check-prefixes=CHECK,CHECK-PIC,CHECK-PIC-LARGE,CHECK-PIC-X64
 @_ZTIi = external constant i8*
 
 define i32 @main() uwtable optsize ssp personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 ; Verify that each basic block section gets its own LSDA exception symbol.
 ;
 ; CHECK-LABEL:        main:
 ; CHECK-NEXT:         .Lfunc_begin0:
 ; CHECK-NEXT:           .cfi_startproc
 
 ;; Verify personality function and LSDA encoding for NON-PIC mode.
-; PersonalityEncoding = dwarf::DW_EH_PE_udata4
-; CHECK-NON-PIC-NEXT:   .cfi_personality 3, __gxx_personality_v0
-; LSDAEncoding = dwarf::DW_EH_PE_udata4
-; CHECK-NON-PIC-NEXT:   .cfi_lsda 3, .Lexception0
+; PersonalityEncoding = dwarf::DW_EH_PE_udata4 (small/medium)
+; PersonalityEncoding = dwarf::DW_EH_PE_absptr (large)
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_personality 0, __gxx_personality_v0
+; LSDAEncoding = dwarf::DW_EH_PE_udata4 (small)
+; LSDAEncoding = dwarf::DW_EH_PE_absptr (medium/large)
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_lsda 3, .Lexception0
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_lsda 0, .Lexception0
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_lsda 0, .Lexception0
 
 ;; Verify personality function and LSDA encoding for PIC mode.
-; PersonalityEncoding = DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4
-; CHECK-PIC-NEXT:       .cfi_personality 155, DW.ref.__gxx_personality_v0
-; LSDAEncoding = DW_EH_PE_pcrel | DW_EH_PE_sdata4
-; CHECK-PIC-NEXT:       .cfi_lsda 27, .Lexception0
+; PersonalityEncoding = DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4 (small/medium)
+; PersonalityEncoding = DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata8 (large)
+; CHECK-PIC-SMALL-NEXT:  .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-MEDIUM-NEXT: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-LARGE-NEXT:  .cfi_personality 156, DW.ref.__gxx_personality_v0
+; LSDAEncoding = DW_EH_PE_pcrel | DW_EH_PE_sdata4 (small)
+; LSDAEncoding = DW_EH_PE_pcrel | DW_EH_PE_sdata8 (medium/large)
+; CHECK-PIC-SMALL-NEXT:  .cfi_lsda 27, .Lexception0
+; CHECK-PIC-MEDIUM-NEXT: .cfi_lsda 28, .Lexception0
+; CHECK-PIC-LARGE-NEXT:  .cfi_lsda 28, .Lexception0
 
 ; CHECK-LABEL:        .Ltmp0:
-; CHECK-NEXT:           callq   _Z1fv
+; CHECK-SMALL-NEXT:     callq   _Z1fv
+; CHECK-MEDIUM-NEXT:    callq   _Z1fv
+; CHECK-NON-PIC-LARGE-NEXT: movabsq $_Z1fv, %rax
+; CHECK-NON-PIC-LARGE-NEXT: callq   *%rax
+; CHECK-PIC-LARGE-NEXT:     movabsq $_Z1fv@GOT, %rax
+; CHECK-PIC-LARGE-NEXT:     callq *(%rbx,%rax)
 ; CHECK-LABEL:        .Ltmp1:
 
 ; CHECK-NOT:            .cfi_lsda
 
 ; CHECK-LABEL:        main.__part.1:
 ; CHECK-NEXT:           .cfi_startproc
 
-; CHECK-NON-PIC-NEXT:   .cfi_personality 3, __gxx_personality_v0
-; CHECK-NON-PIC-NEXT:   .cfi_lsda 3, .Lexception1
-
-; CHECK-PIC-NEXT:       .cfi_personality 155, DW.ref.__gxx_personality_v0
-; CHECK-PIC-NEXT:       .cfi_lsda 27, .Lexception1
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_personality 0, __gxx_personality_v0
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_lsda 3, .Lexception1
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_lsda 0, .Lexception1
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_lsda 0, .Lexception1
+
+; CHECK-PIC-SMALL-NEXT:  .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-MEDIUM-NEXT: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-LARGE-NEXT:  .cfi_personality 156, DW.ref.__gxx_personality_v0
+; CHECK-PIC-SMALL-NEXT:  .cfi_lsda 27, .Lexception1
+; CHECK-PIC-MEDIUM-NEXT: .cfi_lsda 28, .Lexception1
+; CHECK-PIC-LARGE-NEXT:  .cfi_lsda 28, .Lexception1
 
 ; CHECK-NOT:            .cfi_lsda
 
 ; CHECK-LABEL:        main.__part.2:
 ; CHECK-NEXT:           .cfi_startproc
 
-; CHECK-NON-PIC-NEXT:   .cfi_personality 3, __gxx_personality_v0
-; CHECK-NON-PIC-NEXT:   .cfi_lsda 3, .Lexception2
-
-; CHECK-PIC-NEXT:       .cfi_personality 155, DW.ref.__gxx_personality_v0
-; CHECK-PIC-NEXT:       .cfi_lsda 27, .Lexception2
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_personality 3, __gxx_personality_v0
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_personality 0, __gxx_personality_v0
+; CHECK-NON-PIC-SMALL-NEXT:  .cfi_lsda 3, .Lexception2
+; CHECK-NON-PIC-MEDIUM-NEXT: .cfi_lsda 0, .Lexception2
+; CHECK-NON-PIC-LARGE-NEXT:  .cfi_lsda 0, .Lexception2
+
+; CHECK-PIC-SMALL-NEXT:  .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-MEDIUM-NEXT: .cfi_personality 155, DW.ref.__gxx_personality_v0
+; CHECK-PIC-LARGE-NEXT:  .cfi_personality 156, DW.ref.__gxx_personality_v0
+; CHECK-PIC-SMALL-NEXT:  .cfi_lsda 27, .Lexception2
+; CHECK-PIC-MEDIUM-NEXT: .cfi_lsda 28, .Lexception2
+; CHECK-PIC-LARGE-NEXT:  .cfi_lsda 28, .Lexception2
 
 ; CHECK:                nop
 ; CHECK-LABEL:        .Ltmp2:
 ; CHECK-LABEL:        .LBB_END0_2:
 
 ; CHECK-NOT:            .cfi_lsda
 
 entry:

 ;
 ; CHECK:                .section .gcc_except_table
 ; CHECK-NEXT:           .p2align 2
 ; CHECK-NEXT:         GCC_except_table0:
 ; CHECK-NEXT:         .Lexception0:
 
 ;; Verify @LPStart encoding for NON-PIC mode.
 ; CHECK-NON-PIC-NEXT:   .byte 0                       # @LPStart Encoding = absptr
-; CHECK-NON-PIC-NEXT:   .quad main.__part.2
+; CHECK-NON-PIC-X64-NEXT: .quad main.__part.2
+; CHECK-NON-PIC-X32-NEXT: .long main.__part.2
 
 ;; Verify @LPStart encoding for PIC mode.
 ; CHECK-PIC-NEXT:       .byte 16                      # @LPStart Encoding = pcrel
 ; CHECK-PIC-NEXT:     [[DOT:\.Ltmp[0-9]+]]:
-; CHECK-PIC-NEXT:       .quad main.__part.2-[[DOT]]
+; CHECK-PIC-X64-NEXT:   .quad main.__part.2-[[DOT]]
+; CHECK-PIC-X32-NEXT:   .long main.__part.2-[[DOT]]
 
 ;; Verify @TType encoding for NON-PIC mode.
-; CHECK-NON-PIC-NEXT:   .byte 3                       # @TType Encoding = udata4
+; CHECK-NON-PIC-SMALL-NEXT:  .byte  3               # @TType Encoding = udata4
+; CHECK-NON-PIC-MEDIUM-NEXT: .byte  0               # @TType Encoding = absptr
+; CHECK-NON-PIC-LARGE-NEXT:  .byte  0               # @TType Encoding = absptr
 
 ;; Verify @TType encoding for PIC mode.
-; CHECK-PIC-NEXT:       .byte 156                       # @TType Encoding = indirect pcrel sdata8
+; CHECK-PIC-SMALL-NEXT: .byte 155                       # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-MEDIUM-NEXT:.byte 155                       # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-LARGE-NEXT: .byte 156                       # @TType Encoding = indirect pcrel sdata8
 
 ; CHECK-NEXT:           .uleb128 .Lttbase0-.Lttbaseref0
 ; CHECK-NEXT:         .Lttbaseref0:
 ; CHECK-NEXT:           .byte 1                       # Call site Encoding = uleb128
 ; CHECK-NEXT:           .uleb128 .Laction_table_base0-.Lcst_begin0
 ; CHECK-NEXT:         .Lcst_begin0:
 ; CHECK-NEXT:           .uleb128 .Ltmp0-.Lfunc_begin0   # >> Call Site 1 <<
 ; CHECK-NEXT:           .uleb128 .Ltmp1-.Ltmp0          #   Call between .Ltmp0 and .Ltmp1
-; CHECK-NEXT:           .uleb128 .Ltmp2-main.__part.2          #     jumps to .Ltmp2
+; CHECK-NEXT:           .uleb128 .Ltmp2-main.__part.2   #     jumps to .Ltmp2
 ; CHECK-NEXT:           .byte 3                       #   On action: 2
 ; CHECK-NEXT:           .p2align  2
 ; CHECK-NEXT:         .Lexception1:
 
 ; CHECK-NON-PIC-NEXT:   .byte 0                       # @LPStart Encoding = absptr
-; CHECK-NON-PIC-NEXT:   .quad main.__part.2
+; CHECK-NON-PIC-X64-NEXT: .quad main.__part.2
+; CHECK-NON-PIC-X32-NEXT: .long main.__part.2
 
 ; CHECK-PIC-NEXT:       .byte 16                      # @LPStart Encoding = pcrel
 ; CHECK-PIC-NEXT:     [[DOT:\.Ltmp[0-9]+]]:
-; CHECK-PIC-NEXT:       .quad main.__part.2-[[DOT]]
+; CHECK-PIC-X64-NEXT:   .quad main.__part.2-[[DOT]]
+; CHECK-PIC-X32-NEXT:   .long main.__part.2-[[DOT]]
 
-; CHECK-NON-PIC-NEXT:   .byte 3                       # @TType Encoding = udata4
-
-; CHECK-PIC-NEXT:       .byte 156                       # @TType Encoding = indirect pcrel sdata8
+; CHECK-NON-PIC-SMALL-NEXT:  .byte  3               # @TType Encoding = udata4
+; CHECK-NON-PIC-MEDIUM-NEXT: .byte  0               # @TType Encoding = absptr
+; CHECK-NON-PIC-LARGE-NEXT:  .byte  0               # @TType Encoding = absptr
+
+; CHECK-PIC-SMALL-NEXT: .byte 155                       # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-MEDIUM-NEXT:.byte 155                       # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-LARGE-NEXT: .byte 156                       # @TType Encoding = indirect pcrel sdata8
 
 ; CHECK-NEXT:           .uleb128 .Lttbase0-.Lttbaseref1
 ; CHECK-NEXT:         .Lttbaseref1:
 ; CHECK-NEXT:           .byte 1                       # Call site Encoding = uleb128
 ; CHECK-NEXT:           .uleb128 .Laction_table_base0-.Lcst_begin1
 ; CHECK-NEXT:         .Lcst_begin1:
 ; CHECK-NEXT:           .p2align 2
 ; CHECK-NEXT:         .Lexception2:
 
 ; CHECK-NON-PIC-NEXT:   .byte 0                       # @LPStart Encoding = absptr
-; CHECK-NON-PIC-NEXT:   .quad main.__part.2
+; CHECK-NON-PIC-X64-NEXT: .quad main.__part.2
+; CHECK-NON-PIC-X32-NEXT: .long main.__part.2
 
 ; CHECK-PIC-NEXT:       .byte 16                      # @LPStart Encoding = pcrel
 ; CHECK-PIC-NEXT:     [[DOT:\.Ltmp[0-9]+]]:
-; CHECK-PIC-NEXT:       .quad main.__part.2-[[DOT]]
-
-; CHECK-NON-PIC-NEXT:   .byte 3                       # @TType Encoding = udata4
+; CHECK-PIC-X64-NEXT:   .quad main.__part.2-[[DOT]]
+; CHECK-PIC-X32-NEXT:   .long main.__part.2-[[DOT]]
 
-; CHECK-PIC-NEXT:       .byte 156                       # @TType Encoding = indirect pcrel sdata8
+; CHECK-NON-PIC-SMALL-NEXT:  .byte  3               # @TType Encoding = udata4
+; CHECK-NON-PIC-MEDIUM-NEXT: .byte  0               # @TType Encoding = absptr
+; CHECK-NON-PIC-LARGE-NEXT:  .byte  0               # @TType Encoding = absptr
+
+; CHECK-PIC-SMALL-NEXT:  .byte 155                      # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-MEDIUM-NEXT: .byte 155                      # @TType Encoding = indirect pcrel sdata4
+; CHECK-PIC-LARGE-NEXT:  .byte 156                      # @TType Encoding = indirect pcrel sdata8
 
 ; CHECK-NEXT:           .uleb128 .Lttbase0-.Lttbaseref2
 ; CHECK-NEXT:         .Lttbaseref2:
 ; CHECK-NEXT:           .byte 1                       # Call site Encoding = uleb128
 ; CHECK-NEXT:           .uleb128 .Laction_table_base0-.Lcst_begin2
 ; CHECK-NEXT:         .Lcst_begin2:
 ; CHECK-NEXT:           .uleb128 main.__part.2-main.__part.2          # >> Call Site 2 <<
 ; CHECK-NEXT:           .uleb128 .LBB_END0_2-main.__part.2     #   Call between main.__part.2 and .LBB_END0_2
 ; CHECK-NEXT:           .byte 0                       #     has no landing pad
 ; CHECK-NEXT:           .byte 0                       #   On action: cleanup
 ; CHECK-NEXT:         .Laction_table_base0:
 ; CHECK-NEXT:           .byte 0                       # >> Action Record 1 <<
 ; CHECK-NEXT:                                           #   Cleanup
 ; CHECK-NEXT:           .byte 0                       #   No further actions
 ; CHECK-NEXT:           .byte 1                       # >> Action Record 2 <<
 ; CHECK-NEXT:                                           #   Catch TypeInfo 1
 ; CHECK-NEXT:           .byte 125                     #   Continue to action 1
 ; CHECK-NEXT:           .p2align 2
 ; CHECK-NEXT:                                           # >> Catch TypeInfos <<
 
-; CHECK-NON-PIC-NEXT:   .long _ZTIi                     # TypeInfo 1
+; CHECK-NON-PIC-SMALL-NEXT:  .long _ZTIi                # TypeInfo 1
+; CHECK-NON-PIC-MEDIUM-NEXT: .quad _ZTIi                # TypeInfo 1
+; CHECK-NON-PIC-LARGE-NEXT:  .quad _ZTIi                # TypeInfo 1
 
 ; CHECK-PIC-NEXT:     [[DOT:\.Ltmp[0-9]+]]:
-; CHECK-PIC-NEXT:       .quad .L_ZTIi.DW.stub-[[DOT]]
+; CHECK-PIC-SMALL-NEXT:  .long .L_ZTIi.DW.stub-[[DOT]]
+; CHECK-PIC-MEDIUM-NEXT: .long .L_ZTIi.DW.stub-[[DOT]]
+; CHECK-PIC-LARGE-NEXT:  .quad .L_ZTIi.DW.stub-[[DOT]]
 
 ; CHECK-NEXT:         .Lttbase0:
 ; CHECK-NEXT:           .p2align 2
 ; CHECK-NEXT:                                           # -- End function