Fixup TCG for SH-4 FPU instructions fipr and ftrv

[PATCH 0/2] Fixup TCG for SH-4 FPU instructions fipr and ftrv

Randy Schifflin posted 2 patches 3 weeks, 5 days ago

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Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20260629-fixup-sh4-tcg-fpu-instructions-b4-v1-0-4356b305f971@gmail.com

Maintainers: Yoshinori Sato <yoshinori.sato@nifty.com>

target/sh4/op_helper.c        |  2 +-
target/sh4/translate.c        | 15 +++----
tests/tcg/sh4/Makefile.target |  7 +++
tests/tcg/sh4/test-fpu-fipr.c | 64 ++++++++++++++++++++++++++++
tests/tcg/sh4/test-fpu-ftrv.c | 99 +++++++++++++++++++++++++++++++++++++++++++
5 files changed, 176 insertions(+), 11 deletions(-)

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[PATCH 0/2] Fixup TCG for SH-4 FPU instructions fipr and ftrv

Posted by Randy Schifflin 3 weeks, 5 days ago

SH-4 manual for reference: 
https://0x04.net/~mwk/doc/sh/e602156_sh4.pdf

There are two issues with the current TCG code generation
for the `fipr` and `ftrv` instructions. Firstly, they incorrectly
check that the PR flag of the FPSCR register is high. The manual
states these instructions are only defined when that flag is 0.
Secondly, they take as operands a vector index 0-3, but treat
them as offsets into the floating point register list. Vectors
span four floating point registers, and thus each index needs to be
multiplied by 4 to translate to the correct register offset.

This PR adds simple TCG tests for the `fipr` and `ftrv` instructions,
and fixes the issues above by ensuring the PR flag of FPSCR is 0 and
properly translating the vector index operand to its register offset.

Signed-off-by: Randy Schifflin <randy.schifflin@gmail.com>
---
Randy Schifflin (2):
      target/sh4: add tests for sh4 fipr and ftrv instructions
      target/sh4: fixup tcg for sh4 fipr/ftrv instructions

 target/sh4/op_helper.c        |  2 +-
 target/sh4/translate.c        | 15 +++----
 tests/tcg/sh4/Makefile.target |  7 +++
 tests/tcg/sh4/test-fpu-fipr.c | 64 ++++++++++++++++++++++++++++
 tests/tcg/sh4/test-fpu-ftrv.c | 99 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 176 insertions(+), 11 deletions(-)
---
base-commit: 30e8a06b64aa58a3990ba39cb5d09531e7d265e0
change-id: 20260629-fixup-sh4-tcg-fpu-instructions-b4-963cdafd33bf

Best regards,
-- 
Randy Schifflin <randy.schifflin@gmail.com>

Re: [PATCH 0/2] Fixup TCG for SH-4 FPU instructions fipr and ftrv

Posted by Michael Tokarev 2 weeks, 3 days ago

On 30.06.2026 00:49, Randy Schifflin wrote:
> SH-4 manual for reference:
> https://0x04.net/~mwk/doc/sh/e602156_sh4.pdf
> 
> There are two issues with the current TCG code generation
> for the `fipr` and `ftrv` instructions. Firstly, they incorrectly
> check that the PR flag of the FPSCR register is high. The manual
> states these instructions are only defined when that flag is 0.
> Secondly, they take as operands a vector index 0-3, but treat
> them as offsets into the floating point register list. Vectors
> span four floating point registers, and thus each index needs to be
> multiplied by 4 to translate to the correct register offset.
> 
> This PR adds simple TCG tests for the `fipr` and `ftrv` instructions,
> and fixes the issues above by ensuring the PR flag of FPSCR is 0 and
> properly translating the vector index operand to its register offset.
> 
> Signed-off-by: Randy Schifflin <randy.schifflin@gmail.com>
> ---
> Randy Schifflin (2):
>        target/sh4: add tests for sh4 fipr and ftrv instructions
>        target/sh4: fixup tcg for sh4 fipr/ftrv instructions
> 
>   target/sh4/op_helper.c        |  2 +-
>   target/sh4/translate.c        | 15 +++----
>   tests/tcg/sh4/Makefile.target |  7 +++
>   tests/tcg/sh4/test-fpu-fipr.c | 64 ++++++++++++++++++++++++++++
>   tests/tcg/sh4/test-fpu-ftrv.c | 99 +++++++++++++++++++++++++++++++++++++++++++
>   5 files changed, 176 insertions(+), 11 deletions(-)


This looks like qemu-stable material.
I'm picking this up for currently active qemu-stable series.
Please let me know if I should not.

It'd be nice to have the testcase applied to master too (I'll
pick it up for stable series as well, if I wont forget :)

Thanks,

/mjt