target/arm: Use float*_muladd_scalbn

Use the scalbn interface instead of float_muladd_halve_result.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/arm/tcg/helper-a64.c

diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c
index 0e13050..3b226da 100644
--- a/target/arm/tcg/helper-a64.c
+++ b/target/arm/tcg/helper-a64.c
@@ -262,7 +262,7 @@
         (float16_is_infinity(b) && float16_is_zero(a))) {
         return float16_one_point_five;
     }
-    return float16_muladd(a, b, float16_three, float_muladd_halve_result, fpst);
+    return float16_muladd_scalbn(a, b, float16_three, -1, 0, fpst);
 }
 
 float32 HELPER(rsqrtsf_f32)(float32 a, float32 b, float_status *fpst)
@@ -275,7 +275,7 @@
         (float32_is_infinity(b) && float32_is_zero(a))) {
         return float32_one_point_five;
     }
-    return float32_muladd(a, b, float32_three, float_muladd_halve_result, fpst);
+    return float32_muladd_scalbn(a, b, float32_three, -1, 0, fpst);
 }
 
 float64 HELPER(rsqrtsf_f64)(float64 a, float64 b, float_status *fpst)
@@ -288,7 +288,7 @@
         (float64_is_infinity(b) && float64_is_zero(a))) {
         return float64_one_point_five;
     }
-    return float64_muladd(a, b, float64_three, float_muladd_halve_result, fpst);
+    return float64_muladd_scalbn(a, b, float64_three, -1, 0, fpst);
 }
 
 /* Floating-point reciprocal exponent - see FPRecpX in ARM ARM */