[llvm] r353480 - [mips][micromips] Fix how values in .gcc_except_table are calculated
Hans Wennborg via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 12 03:04:56 PST 2019
Merged to 8.0 in r353827.
On Thu, Feb 7, 2019 at 11:57 PM Petar Jovanovic via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
>
> Author: petarj
> Date: Thu Feb 7 14:57:33 2019
> New Revision: 353480
>
> URL: http://llvm.org/viewvc/llvm-project?rev=353480&view=rev
> Log:
> [mips][micromips] Fix how values in .gcc_except_table are calculated
>
> When a landing pad is calculated in a program that is compiled for micromips
> with -fPIC flag, it will point to an even address.
> Such an error will cause a segmentation fault, as the instructions in
> micromips are aligned on odd addresses. This patch sets the last bit of the
> offset where a landing pad is, to 1, which will effectively be an odd
> address and point to the instruction exactly.
>
> r344591 fixed this issue for -static compilation.
>
> Patch by Aleksandar Beserminji.
>
> Differential Revision: https://reviews.llvm.org/D57677
>
> Modified:
> llvm/trunk/lib/MC/MCExpr.cpp
> llvm/trunk/test/CodeGen/Mips/micromips-b-range.ll
> llvm/trunk/test/DebugInfo/Mips/eh_frame.ll
>
> Modified: llvm/trunk/lib/MC/MCExpr.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCExpr.cpp?rev=353480&r1=353479&r2=353480&view=diff
> ==============================================================================
> --- llvm/trunk/lib/MC/MCExpr.cpp (original)
> +++ llvm/trunk/lib/MC/MCExpr.cpp Thu Feb 7 14:57:33 2019
> @@ -558,6 +558,11 @@ static void AttemptToFoldSymbolOffsetDif
> if (Asm->isThumbFunc(&SA))
> Addend |= 1;
>
> + // If symbol is labeled as micromips, we set low-bit to ensure
> + // correct offset in .gcc_except_table
> + if (Asm->getBackend().isMicroMips(&SA))
> + Addend |= 1;
> +
> // Clear the symbol expr pointers to indicate we have folded these
> // operands.
> A = B = nullptr;
>
> Modified: llvm/trunk/test/CodeGen/Mips/micromips-b-range.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Mips/micromips-b-range.ll?rev=353480&r1=353479&r2=353480&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/Mips/micromips-b-range.ll (original)
> +++ llvm/trunk/test/CodeGen/Mips/micromips-b-range.ll Thu Feb 7 14:57:33 2019
> @@ -13,7 +13,7 @@
> ; CHECK-NEXT: 1e: fb fd 00 00 sw $ra, 0($sp)
> ; CHECK-NEXT: 22: 41 a1 00 01 lui $1, 1
> ; CHECK-NEXT: 26: 40 60 00 02 bal 8 <foo+0x2e>
> -; CHECK-NEXT: 2a: 30 21 04 68 addiu $1, $1, 1128
> +; CHECK-NEXT: 2a: 30 21 04 69 addiu $1, $1, 1129
> ; CHECK-NEXT: 2e: 00 3f 09 50 addu $1, $ra, $1
> ; CHECK-NEXT: 32: ff fd 00 00 lw $ra, 0($sp)
> ; CHECK-NEXT: 36: 00 01 0f 3c jr $1
> @@ -27,7 +27,7 @@
> ; CHECK-NEXT: 56: fb fd 00 00 sw $ra, 0($sp)
> ; CHECK-NEXT: 5a: 41 a1 00 01 lui $1, 1
> ; CHECK-NEXT: 5e: 40 60 00 02 bal 8 <foo+0x66>
> -; CHECK-NEXT: 62: 30 21 04 5c addiu $1, $1, 1116
> +; CHECK-NEXT: 62: 30 21 04 5d addiu $1, $1, 1117
> ; CHECK-NEXT: 66: 00 3f 09 50 addu $1, $ra, $1
> ; CHECK-NEXT: 6a: ff fd 00 00 lw $ra, 0($sp)
> ; CHECK-NEXT: 6e: 00 01 0f 3c jr $1
> @@ -39,7 +39,7 @@
> ; CHECK-NEXT: 86: fb fd 00 00 sw $ra, 0($sp)
> ; CHECK-NEXT: 8a: 41 a1 00 01 lui $1, 1
> ; CHECK-NEXT: 8e: 40 60 00 02 bal 8 <foo+0x96>
> -; CHECK-NEXT: 92: 30 21 04 2c addiu $1, $1, 1068
> +; CHECK-NEXT: 92: 30 21 04 2d addiu $1, $1, 1069
> ; CHECK-NEXT: 96: 00 3f 09 50 addu $1, $ra, $1
> ; CHECK-NEXT: 9a: ff fd 00 00 lw $ra, 0($sp)
> ; CHECK-NEXT: 9e: 00 01 0f 3c jr $1
> @@ -51,7 +51,7 @@
> ; CHECK-NEXT: 10476: fb fd 00 00 sw $ra, 0($sp)
> ; CHECK-NEXT: 1047a: 41 a1 00 01 lui $1, 1
> ; CHECK-NEXT: 1047e: 40 60 00 02 bal 8 <foo+0x10486>
> -; CHECK-NEXT: 10482: 30 21 04 00 addiu $1, $1, 1024
> +; CHECK-NEXT: 10482: 30 21 04 01 addiu $1, $1, 1025
> ; CHECK-NEXT: 10486: 00 3f 09 50 addu $1, $ra, $1
> ; CHECK-NEXT: 1048a: ff fd 00 00 lw $ra, 0($sp)
> ; CHECK-NEXT: 1048e: 00 01 0f 3c jr $1
>
> Modified: llvm/trunk/test/DebugInfo/Mips/eh_frame.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/Mips/eh_frame.ll?rev=353480&r1=353479&r2=353480&view=diff
> ==============================================================================
> --- llvm/trunk/test/DebugInfo/Mips/eh_frame.ll (original)
> +++ llvm/trunk/test/DebugInfo/Mips/eh_frame.ll Thu Feb 7 14:57:33 2019
> @@ -1,9 +1,21 @@
> -; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -O3 -filetype=obj -o - %s | llvm-readelf -r | FileCheck %s
> +; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -relocation-model=static -O3 -filetype=obj -o - %s | \
> +; RUN: llvm-readelf -r | FileCheck %s --check-prefix=CHECK-READELF
> +; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -relocation-model=pic -O3 -filetype=obj -o - %s | \
> +; RUN: llvm-readelf -r | FileCheck %s --check-prefix=CHECK-READELF
> +; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -relocation-model=static -O3 -filetype=obj -o - %s | \
> +; RUN: llvm-objdump -s -j .gcc_except_table - | FileCheck %s --check-prefix=CHECK-EXCEPT-TABLE-STATIC
> +; RUN: llc -mtriple mips-unknown-linux-gnu -mattr=+micromips -relocation-model=pic -O3 -filetype=obj -o - %s | \
> +; RUN: llvm-objdump -s -j .gcc_except_table - | FileCheck %s --check-prefix=CHECK-EXCEPT-TABLE-PIC
>
> -; CHECK: .rel.eh_frame
> -; CHECK: DW.ref.__gxx_personality_v0
> -; CHECK-NEXT: .text
> -; CHECK-NEXT: .gcc_except_table
> +; CHECK-READELF: .rel.eh_frame
> +; CHECK-READELF: DW.ref.__gxx_personality_v0
> +; CHECK-READELF-NEXT: .text
> +; CHECK-READELF-NEXT: .gcc_except_table
> +
> +; CHECK-EXCEPT-TABLE-STATIC: 0000 ff9b1501 0c011500 00150e23 01231e00 ...........#.#..
> +; CHECK-EXCEPT-TABLE-STATIC: 0010 00010000 00000000
> +; CHECK-EXCEPT-TABLE-PIC: 0000 ff9b1501 0c012d00 002d133f 013f2a00 ......-..-.?.?*.
> +; CHECK-EXCEPT-TABLE-PIC: 0010 00010000 00000000 ........
>
> @_ZTIi = external constant i8*
>
>
>
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