1 files changed, 100 insertions, 0 deletions
diff --git a/tests/tst-immediate-exactness.c b/tests/tst-immediate-exactness.c
new file mode 100644
index 0000000..ed054e7
--- /dev/null
+++ b/tests/tst-immediate-exactness.c
@@ -0,0 +1,100 @@
+#include <stdio.h>
+#include <string.h>
+#include <libmcpu.h>
+#include "../utils/mcpu-asm.h"
+
+#define CHECK(c,m) do { if(!(c)) { fprintf(stderr,"FAIL: %s\n",m); return 1; } } while(0)
+
+static int
+rejected( const char *src, const char *needle )
+{
+  cpu_asm_image im;
+  char err[512];
+  int rc = cpu_assemble_text( src, &im, err, sizeof( err ) );
+  if( rc == 0 )
+  {
+    cpu_asm_image_free( &im );
+    return( 0 );
+  }
+  return( strstr( err, needle ) != 0 );
+}
+
+int
+main( void )
+{
+  cpu_asm_image im;
+  char err[512];
+  static const char *prec = "3.14243987129849274029174912694696912849214e-286";
+  char src[4096];
+
+  __cpu_init();
+
+  CHECK( cpu_assemble_text( ".text\nLDR r32@0x00000, -17.0\nHALT\n", &im, err, sizeof( err ) ) == 0,
+        "exact real32 LDR accepted");
+  cpu_asm_image_free( &im );
+
+  CHECK( cpu_assemble_text( ".text\nLDR r4096@0x00000, 2.0\nHALT\n", &im, err, sizeof( err ) ) == 0,
+        "exact real64 immediate widened to real4096 accepted");
+  cpu_asm_image_free( &im );
+
+  CHECK( rejected( ".text\nLDR r32@0x00000, 0.1\nHALT\n",
+        "LDR immediate is not exactly representable as real32;"),
+        "inexact real32 immediate rejected");
+
+  CHECK( rejected( ".text\nLDR r64@0x00000, 0.1\nHALT\n",
+        "LDR immediate is not exactly representable as real64;"),
+        "inexact real64 immediate rejected");
+
+  snprintf( src, sizeof( src ), ".text\nLDR r64@0x00000, %s\nHALT\n", prec );
+  CHECK( rejected( src, "LDR immediate is not exactly representable as real64;" ),
+        "inexact real64 immediate rejected");
+
+  snprintf( src, sizeof( src ), ".text\nLDR r4096@0x00000, %s\nHALT\n", prec );
+  CHECK( rejected( src, "LDR immediate is not exactly representable as real64;" ),
+        "wide LDR cannot hide binary64 precision loss");
+
+  CHECK( cpu_assemble_text( ".text\nLDC c64@0x00000, -17.0r0+32.0j0\nHALT\n", &im, err, sizeof( err ) ) == 0,
+        "exact complex64 immediate accepted");
+  cpu_asm_image_free( &im );
+
+  CHECK( rejected( ".text\nLDC c128@0x00000, 0.1r0+32.0j0\nHALT\n",
+        "LDC immediate component is not exactly representable as real32;"),
+        "inexact complex immediate component rejected");
+
+  CHECK( rejected( ".text\nLDC c32@0x00000, 1.0r0+2.0j0\nHALT\n",
+        "bad LDC destination"),
+        "complex destination below 64 bits rejected");
+
+  CHECK( rejected( ".text\nLDI r128@0x00000, 9223372036854775808\nHALT\n",
+        "LDI immediate is not exactly representable as integer64;"),
+        "integer wider than signed IMM64 rejected");
+
+  CHECK( rejected( ".text\nLDI r8@0x00000, 255\nHALT\n",
+        "LDI immediate is not exactly representable as integer8;"),
+        "narrow integer immediate that changes value rejected");
+  CHECK( cpu_assemble_text( ".text\nLDI r8@0x00000, -1\nHALT\n", &im, err, sizeof( err ) ) == 0,
+        "exact signed integer8 immediate accepted");
+  cpu_asm_image_free( &im );
+
+  snprintf( src, sizeof( src ),
+    ".data\n"
+    ".align 16\n"
+    "wide_real:\n"
+    "  .real 4096, %s\n"
+    "wide_int:\n"
+    "  .integer 128, 9223372036854775808\n"
+    "wide_complex:\n"
+    "  .complex 4096, %s, -%s\n"
+    ".text\n"
+    "  LOAD r4096@0x00000, wide_real\n"
+    "  LOAD r128@0x00200, wide_int\n"
+    "  LOAD c4096@0x00400, wide_complex\n"
+    "  HALT\n", prec, prec, prec);
+  CHECK( cpu_assemble_text( src, &im, err, sizeof( err ) ) == 0,
+        "DATA fallback with .real/.integer/.complex and LOAD accepted");
+  cpu_asm_image_free( &im );
+
+  __cpu_free_context();
+  puts( "libcpu immediate exactness regression: PASS" );
+  return( 0 );
+}