3769ce013b
Each section now tracks the index of the first linker-relaxable fragment, enabling two changes: * Delete redundant ALIGN relocations before the first linker-relaxable instruction in a section. The primary example is the offset 0 R_RISCV_ALIGN relocation for a text section aligned by 4. * For alignments larger than the NOP size after the first linker-relaxable instruction, ALIGN relocations are now generated, even in norelax regions. This fixes the issue #150159. The new test llvm/test/MC/RISCV/Relocations/align-after-relax.s verifies the required ALIGN in a norelax region following linker-relaxable instructions. By using a fragment index within the subsection (which is less than or equal to the section's index), the implementation may generate redundant ALIGN relocations in lower-numbered subsections before the first linker-relaxable instruction. align-option-relax.s demonstrates the ALIGN optimization. Add an initial `call` to a few tests to prevent the ALIGN optimization. --- When the alignment exceeds 2, we insert $alignment-2 bytes of NOPs, even in non-RVC code. This enables non-RVC code following RVC code to handle a 2-byte adjustment without requiring an additional state in MCSection or AsmParser. ``` .globl _start _start: // GNU ld can relax this to 6505 lui a0, 0x1 // LLD hasn't implemented this transformation. lui a0, %hi(foo) .option push .option norelax .option norvc // Now we generate R_RISCV_ALIGN with addend 2, even if this is a norvc region. .balign 4 b0: .word 0x3a393837 .option pop foo: ``` Pull Request: https://github.com/llvm/llvm-project/pull/150816
70 lines
2.3 KiB
ArmAsm
70 lines
2.3 KiB
ArmAsm
# REQUIRES: riscv
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## Test that we can handle --emit-relocs while relaxing.
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# RUN: rm -rf %t && mkdir %t && cd %t
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# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+relax %s -o 32.o -riscv-align-rvc=0
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# RUN: ld.lld -Ttext=0x10000 --emit-relocs 32.o -o 32
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# RUN: llvm-objdump -dr --no-show-raw-insn -M no-aliases 32 | FileCheck %s
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# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+relax %s -o 64.o -riscv-align-rvc=0
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# RUN: ld.lld -Ttext=0x10000 --emit-relocs 64.o -o 64
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# RUN: llvm-objdump -dr --no-show-raw-insn -M no-aliases 64 | FileCheck %s
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## -r should keep original relocations.
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# RUN: ld.lld -r 64.o -o 64.r
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# RUN: llvm-objdump -dr --no-show-raw-insn -M no-aliases 64.r | FileCheck %s --check-prefix=CHECKR
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## --no-relax should keep original relocations.
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# RUN: ld.lld --emit-relocs --no-relax 64.o -o 64.norelax
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# RUN: llvm-objdump -dr --no-show-raw-insn -M no-aliases 64.norelax | FileCheck %s --check-prefix=CHECKNORELAX
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# CHECK: <_start>:
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# CHECK-NEXT: jal ra, 0x10008 <f>
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# CHECK-NEXT: R_RISCV_JAL f
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# CHECK-NEXT: R_RISCV_RELAX *ABS*
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# CHECK-NEXT: jal ra, 0x10008 <f>
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# CHECK-NEXT: R_RISCV_JAL f
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# CHECK-NEXT: R_RISCV_RELAX *ABS*
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# CHECK-EMPTY:
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# CHECK-NEXT: <f>:
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# CHECK-NEXT: jalr zero, 0x0(ra)
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# CHECK-NEXT: R_RISCV_ALIGN *ABS*+0x4
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# CHECKR: <_start>:
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# CHECKR-NEXT: auipc ra, 0x0
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# CHECKR-NEXT: R_RISCV_CALL_PLT f
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# CHECKR-NEXT: R_RISCV_RELAX *ABS*
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# CHECKR-NEXT: jalr ra, 0x0(ra)
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# CHECKR-NEXT: auipc ra, 0x0
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# CHECKR-NEXT: R_RISCV_CALL_PLT f
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# CHECKR-NEXT: R_RISCV_RELAX *ABS*
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# CHECKR-NEXT: jalr ra, 0x0(ra)
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# CHECKR-NEXT: addi zero, zero, 0x0
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# CHECKR-NEXT: R_RISCV_ALIGN *ABS*+0x4
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# CHECKR-EMPTY:
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# CHECKR-NEXT: <f>:
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# CHECKR-NEXT: jalr zero, 0x0(ra)
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# CHECKNORELAX: <_start>:
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# CHECKNORELAX-NEXT: auipc ra, 0x0
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# CHECKNORELAX-NEXT: R_RISCV_CALL_PLT f
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# CHECKNORELAX-NEXT: R_RISCV_RELAX *ABS*
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# CHECKNORELAX-NEXT: jalr ra, 0x10(ra)
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# CHECKNORELAX-NEXT: auipc ra, 0x0
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# CHECKNORELAX-NEXT: R_RISCV_CALL_PLT f
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# CHECKNORELAX-NEXT: R_RISCV_RELAX *ABS*
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# CHECKNORELAX-NEXT: jalr ra, 0x8(ra)
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# CHECKNORELAX-EMPTY:
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# CHECKNORELAX-NEXT: <f>:
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# CHECKNORELAX-NEXT: jalr zero, 0x0(ra)
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# CHECKNORELAX-NEXT: R_RISCV_ALIGN *ABS*+0x4
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.global _start
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_start:
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call f
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call f
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.balign 8
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f:
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ret
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