Pre-calculate pow table for FXTRACT instruction

2025-03-20 21:52:48 +06:00
parent 00c97dac1c
commit a9c97abfb6
4 changed files with 14 additions and 1 deletions
--- a/src/cpu/x87_ops_misc.h
+++ b/src/cpu/x87_ops_misc.h
@@ -46,7 +46,7 @@ opFXTRACT(UNUSED(uint32_t fetchdat))
    test.eind.d = ST(0);
    exp80       = test.eind.ll & 0x7ff0000000000000LL;
    exp80final  = (exp80 >> 52) - BIAS64;
-    mant        = test.eind.d / (pow(2.0, (double) exp80final));
+    mant        = test.eind.d / exp_pow_table[exp80 >> 52];
    ST(0)       = (double) exp80final;
    FP_TAG_VALID;
    x87_push(mant);