From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 3 Jun 2021 22:18:08 +0000 (+0100)
Subject: add c version of double-to-int32
X-Git-Tag: DRAFT_SVP64_0_1~824
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=acd452e32c5680b727b39ee9f469825ed210d1ed;p=libreriscv.git

add c version of double-to-int32
---

diff --git a/openpower/sv/int_fp_mv/appendix.mdwn b/openpower/sv/int_fp_mv/appendix.mdwn
index 1bcd34e68..2d4ca89c9 100644
--- a/openpower/sv/int_fp_mv/appendix.mdwn
+++ b/openpower/sv/int_fp_mv/appendix.mdwn
@@ -1,5 +1,29 @@
 # Equivalent OpenPower ISA v3.0 Assembly Language for FP -> Integer Conversion Modes
 
+## c (IEEE754 standard compliant)
+
+```
+int32_t toInt32(double number)
+{
+    uint32_t result = (int32_t)number;
+    return result;
+}
+```
+
+### 64-bit float -> 32-bit signed integer
+
+```
+toInt32(double):
+        fctiwz 1,1
+        addi 9,1,-16
+        stfiwx 1,0,9
+        lwz 3,-16(1)
+        extsw 3,3
+        blr
+        .long 0
+        .byte 0,9,0,0,0,0,0,0
+```
+
 ## Rust
 
 ```pub fn fcvttgd_rust(v: f64) -> i64 {