PIC medany: Fix parameters of load instruction #446
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| @@ -122,7 +122,7 @@ This model is similar to the medium any code model, but uses the | |||
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| # Calculate address of non-local symbol | |||
| .Ltmp3: auipc a0, %got_pcrel_hi(symbol) | |||
| l[w|d] a0, a0, %pcrel_lo(.Ltmp3) | |||
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Uh, a0 is being use as the base address register here. It's just using the ISA manual's syntax rather than the canonical GNU one by putting the immediate after the register as a separate operand rather than parenthesising the register and putting the immediate before it.
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i.e.:
- l[w|d] a0, a0, %pcrel_lo(.Ltmp3)
+ l[w|d] a0, %pcrel_lo(.Ltmp3)(a0)is the right fix here
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Right. Do you prefer to keep it that way or should I adjust to lw a0, %pcrel_lo(.Ltmp3)(a0)?
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Since all examples in this section focus on RV32, this patch also replaces l[w|d] by lw.
They don't, they are just as valid on RV64 if symbol is an int.
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(it's important here to be clear about the difference between the value and the address, rather than make everything a word, and we don't want to be assuming a specific XLEN either)
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Done.
I guessed that the sequence focuses on 32-bit loads/stores for simplicity (-> RV32).
But you are right that this only affects the size of the value.
When calculating the address, the addi (in the examples above) works for 32-bit and 64-bit addresses.
The explanation of the medium position independent code model includes the instruction `l[w|d] a0, a0, %pcrel_lo(.Ltmp3)` to calculate the address of a non-local symbol. That's not the correct RISC-V syntax for a load instruction. Let's fix that. Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
The explanation of the medium position independent code model
includes the instruction
l[w|d] a0, a0, %pcrel_lo(.Ltmp3)to calculate the address of a non-local symbol.
That's not the correct RISC-V syntax for a load instruction.
Let's fix that.