x86 asm: sqrt x87

2026-01-23 02:05:57 +01:00 · 2019-06-22 00:00:00 +00:00
parent 564735fbfc
commit f66e777337
1 changed files with 15 additions and 0 deletions
--- a/userland/arch/x86_64/inline_asm/sqrt_x87.c
+++ b/userland/arch/x86_64/inline_asm/sqrt_x87.c
@@ -0,0 +1,15 @@
+/* https://github.com/cirosantilli/linux-kernel-module-cheat#gcc-inline-assembly */
+
+#include <assert.h>
+
+int main(void) {
+    double io = 4.0;
+    __asm__ (
+        "fsqrt"
+        : "+t" (io)
+        :
+        :
+    );
+    assert(io == 2.0);
+    return 0;
+}