From 08e185cadb24b038574dad676d4dae8488ba8b6e Mon Sep 17 00:00:00 2001 From: "Lucas Mateus Castro (alqotel)" Date: Fri, 5 Aug 2022 11:15:22 -0300 Subject: [PATCH] target/ppc: Bugfix FP when OE/UE are set When an overflow exception occurs and OE is set the intermediate result should be adjusted (by subtracting from the exponent) to avoid rounding to inf. The same applies to an underflow exceptionion and UE (but adding to the exponent). To do this set the fp_status.rebias_overflow when OE is set and fp_status.rebias_underflow when UE is set as the FPU will recalculate in case of a overflow/underflow if the according rebias* is set. Signed-off-by: Lucas Mateus Castro (alqotel) Reviewed-by: Richard Henderson Message-Id: <20220805141522.412864-3-lucas.araujo@eldorado.org.br> Signed-off-by: Daniel Henrique Barboza --- target/ppc/cpu.c | 2 ++ target/ppc/fpu_helper.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/target/ppc/cpu.c b/target/ppc/cpu.c index 401b6f9e63..0ebac04bc4 100644 --- a/target/ppc/cpu.c +++ b/target/ppc/cpu.c @@ -120,6 +120,8 @@ void ppc_store_fpscr(CPUPPCState *env, target_ulong val) val |= FP_FEX; } env->fpscr = val; + env->fp_status.rebias_overflow = (FP_OE & env->fpscr) ? true : false; + env->fp_status.rebias_underflow = (FP_UE & env->fpscr) ? true : false; if (tcg_enabled()) { fpscr_set_rounding_mode(env); } diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index 7ab6beadad..0f045b70f8 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -348,7 +348,6 @@ static inline int float_overflow_excp(CPUPPCState *env) bool overflow_enabled = !!(env->fpscr & FP_OE); if (overflow_enabled) { - /* XXX: should adjust the result */ /* Update the floating-point enabled exception summary */ env->fpscr |= FP_FEX; /* We must update the target FPR before raising the exception */ @@ -367,7 +366,6 @@ static inline void float_underflow_excp(CPUPPCState *env) /* Update the floating-point exception summary */ env->fpscr |= FP_FX; if (env->fpscr & FP_UE) { - /* XXX: should adjust the result */ /* Update the floating-point enabled exception summary */ env->fpscr |= FP_FEX; /* We must update the target FPR before raising the exception */