From 6c0fab81ff8f559a10e648b2ae7f4d8ab76d3847 Mon Sep 17 00:00:00 2001
From: Tom Herman <tomherman4@gmail.com>
Date: Mon, 9 Dec 2024 19:03:30 +0200
Subject: [PATCH] support bit arithmetic shift right

---
 flipjump/stl/bit/shifts.fj                  |  8 ++++++
 programs/simple_math_checks/shra.fj         | 29 +++++++++++++++++++++
 tests/inout/simple_math_checks/25equals.out | 25 ++++++++++++++++++
 tests/tests_tables/test_compile_slow.csv    |  2 ++
 tests/tests_tables/test_run_slow.csv        |  2 ++
 5 files changed, 66 insertions(+)
 create mode 100644 programs/simple_math_checks/shra.fj
 create mode 100644 tests/inout/simple_math_checks/25equals.out

diff --git a/flipjump/stl/bit/shifts.fj b/flipjump/stl/bit/shifts.fj
index 5bd3c63..5c4270f 100644
--- a/flipjump/stl/bit/shifts.fj
+++ b/flipjump/stl/bit/shifts.fj
@@ -16,6 +16,14 @@ ns bit {
         .zero times, x+(n-times)*dw
     }
 
+    // Complexity: n(2@-1)
+    //   x[:n] >>= times (arithmetic shift right)
+    // times is a constant.
+    def shra n, times, x {
+        rep(n-times, i) .mov x+i*dw, x+(i+times)*dw
+        rep(times-1, i) .mov x+(n-1-(i+1))*dw, x+(n-1)*dw
+    }
+
 
     // Complexity: n(2@-1)
     //   x[:n] <<= 1
diff --git a/programs/simple_math_checks/shra.fj b/programs/simple_math_checks/shra.fj
new file mode 100644
index 0000000..4a50922
--- /dev/null
+++ b/programs/simple_math_checks/shra.fj
@@ -0,0 +1,29 @@
+stl.startup
+
+SHRA_BIT_NUM = 0xe71e3e4a716549fb31fc565d0dbb2f96c846c32ee4018325d1cd59436959489e67e9c48d3c4861da188988ead4f9fefab18e0c51c22c7241405f456ff95023b9cec204245f9bc9285cdead281e5aef9458296a4036cdb03ffcece333cb5c2d05fd66ddf091b82de8e16bc08b648ab018a3f05a1d812f94223419680ea44e0b11121da44b5bdf7f55a1346ea0d69a244177005a266bfb233372c7e12a8b6f76a39c1364624820a19d395f224d19d91fb6f535c8d485420d4c6520065687092d730d5257944ce12a5e
+rep(25, i) test_shra 32, (SHRA_BIT_NUM>>(37*i))&((1<<32)-1), (SHRA_BIT_NUM>>(37*i + 32))&((1<<5)-1)
+
+stl.loop
+
+
+hex.init
+
+def test_shra n, x, shift @ lt, eq, gt, xh, ch, end {
+    bit.shra n, shift, xh
+    bit.cmp n, xh, ch, lt, eq, gt
+
+  lt:
+    stl.output '<'
+    ;end
+  eq:
+    stl.output '='
+    ;end
+  gt:
+    stl.output '>'
+    ;end
+
+  xh: bit.vec n, x
+  ch: bit.vec n, x&(1<<(n-1)) ? ((x>>shift)&((1<<n)-1)) | (((1<<shift)-1) << (n-shift)) : (x>>shift)&((1<<n)-1)
+  end:
+    stl.output '\n'
+}
\ No newline at end of file
diff --git a/tests/inout/simple_math_checks/25equals.out b/tests/inout/simple_math_checks/25equals.out
new file mode 100644
index 0000000..344a662
--- /dev/null
+++ b/tests/inout/simple_math_checks/25equals.out
@@ -0,0 +1,25 @@
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
+=
diff --git a/tests/tests_tables/test_compile_slow.csv b/tests/tests_tables/test_compile_slow.csv
index 7140f91..33e05af 100644
--- a/tests/tests_tables/test_compile_slow.csv
+++ b/tests/tests_tables/test_compile_slow.csv
@@ -1,5 +1,7 @@
 hex_func7, programs/func_tests/func7.fj,tests/compiled/func_tests/func7.fjm, 64,3,0, True,True
 
+shra, programs/simple_math_checks/shra.fj,tests/compiled/simple_math_checks/shra.fjm, 64,3,0, True,True
+
 calc, programs/calc.fj,tests/compiled/calc.fjm, 64,3,0, True,True
 
 hex_func1, programs/func_tests/func1.fj,tests/compiled/func_tests/func1.fjm, 64,3,0, True,True
diff --git a/tests/tests_tables/test_run_slow.csv b/tests/tests_tables/test_run_slow.csv
index 188314f..e3fc2f1 100644
--- a/tests/tests_tables/test_run_slow.csv
+++ b/tests/tests_tables/test_run_slow.csv
@@ -1,5 +1,7 @@
 hex_func7, tests/compiled/func_tests/func7.fjm, ,tests/inout/func_tests/func7.out, False,False
 
+shra, tests/compiled/simple_math_checks/shra.fjm, ,tests/inout/simple_math_checks/25equals.out, False,False
+
 calc1, tests/compiled/calc.fjm, tests/inout/calc_tests/calc1.in,tests/inout/calc_tests/calc1.out, False,False
 calc2, tests/compiled/calc.fjm, tests/inout/calc_tests/calc2.in,tests/inout/calc_tests/calc2.out, False,False
 calc3, tests/compiled/calc.fjm, tests/inout/calc_tests/calc3.in,tests/inout/calc_tests/calc3.out, False,False