diff mbox series

[v2,10/12] fpu: Always decide snan_bit_is_one() at runtime

Message ID 20250224111524.1101196-11-peter.maydell@linaro.org
State New
Headers show
Series fpu: Remove remaining target ifdefs and build only once | expand

Commit Message

Peter Maydell Feb. 24, 2025, 11:15 a.m. UTC 
Currently we have a compile-time shortcut where we return a hardcode
value from snan_bit_is_one() on everything except MIPS, because we
know that's the only target that needs to change
status->no_signaling_nans at runtime.

Remove the ifdef, so we always look at the status flag.  This means
we must update the two targets (HPPA and SH4) that were previously
hardcoded to return true so that they set the status flag correctly.

This has no behavioural change, but will be necessary if we want to
build softfloat once for all targets.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250217125055.160887-9-peter.maydell@linaro.org
---
 target/hppa/fpu_helper.c       | 1 +
 target/sh4/cpu.c               | 1 +
 fpu/softfloat-specialize.c.inc | 7 -------
 3 files changed, 2 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c
index 8ff4b448049..a62d9d30831 100644
--- a/target/hppa/fpu_helper.c
+++ b/target/hppa/fpu_helper.c
@@ -67,6 +67,7 @@  void HELPER(loaded_fr0)(CPUHPPAState *env)
     set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->fp_status);
     /* Default NaN: sign bit clear, msb-1 frac bit set */
     set_float_default_nan_pattern(0b00100000, &env->fp_status);
+    set_snan_bit_is_one(true, &env->fp_status);
     /*
      * "PA-RISC 2.0 Architecture" says it is IMPDEF whether the flushing
      * enabled by FPSR.D happens before or after rounding. We pick "before"
diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c
index 4ac693d99bd..ccfe222bdf3 100644
--- a/target/sh4/cpu.c
+++ b/target/sh4/cpu.c
@@ -128,6 +128,7 @@  static void superh_cpu_reset_hold(Object *obj, ResetType type)
     set_flush_to_zero(1, &env->fp_status);
 #endif
     set_default_nan_mode(1, &env->fp_status);
+    set_snan_bit_is_one(true, &env->fp_status);
     /* sign bit clear, set all frac bits other than msb */
     set_float_default_nan_pattern(0b00111111, &env->fp_status);
     /*
diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc
index a2c6afad5da..ba4fa08b7be 100644
--- a/fpu/softfloat-specialize.c.inc
+++ b/fpu/softfloat-specialize.c.inc
@@ -93,17 +93,10 @@  static inline bool no_signaling_nans(float_status *status)
  * In IEEE 754-1985 this was implementation defined, but in IEEE 754-2008
  * the msb must be zero.  MIPS is (so far) unique in supporting both the
  * 2008 revision and backward compatibility with their original choice.
- * Thus for MIPS we must make the choice at runtime.
  */
 static inline bool snan_bit_is_one(float_status *status)
 {
-#if defined(TARGET_MIPS)
     return status->snan_bit_is_one;
-#elif defined(TARGET_HPPA) || defined(TARGET_SH4)
-    return 1;
-#else
-    return 0;
-#endif
 }
 
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