Updated solution

1 files changed, 43 insertions, 0 deletions

diff --git a/bomblab/phase4.asm b/bomblab/phase4.asm
new file mode 100644
index 0000000..f0c5a85
--- /dev/null
+++ b/bomblab/phase4.asm
@@ -0,0 +1,43 @@
+# OBJDUMP
+0000000000400fce <func4>:
+  400fce:	48 83 ec 08          	sub    $0x8,%rsp
+
+  400fd2:	89 d0                	mov    %right,%range
+  400fd4:	29 f0                	sub    %left,%range
+  400fd6:	89 c1                	mov    %range,%mid
+  400fd8:	c1 e9 1f             	shr    $0x1f,%mid
+  400fdb:	01 c8                	add    %mid,%range
+  400fdd:	d1 f8                	sar    $1,%range
+  400fdf:	8d 0c 30             	lea    (%range,%left,1),%mid
+  400fe2:	39 f9                	cmp    %input,%mid
+  # range = right - left
+  # mid = left + (range/2)
+
+
+  400fe4:	7e 0c                	jle    400ff2 <func4+0x24>          # if (mid > input), left part
+
+  # left part
+  # [left, mid-1]
+  400fe6:	8d 51 ff             	lea    -0x1(%mid),%right            # right = mid - 1
+  400fe9:	e8 e0 ff ff ff       	call   400fce <func4>
+  400fee:	01 c0                	add    %range,%range                # range = 2 * range
+  400ff0:	eb 15                	jmp    401007 <func4+0x39>
+
+  # right part
+  # [mid+1, right]
+  400ff2:	b8 00 00 00 00       	mov    $0x0,%range
+  400ff7:	39 f9                	cmp    %input,%mid
+  400ff9:	7d 0c                	jge    401007 <func4+0x39>          # if (mid >= input) ret
+  400ffb:	8d 71 01             	lea    0x1(%mid),%left              # left = mid + 1
+  400ffe:	e8 cb ff ff ff       	call   400fce <func4>
+  401003:	8d 44 00 01          	lea    0x1(%range,%range,1),%range  # range = 2*range + 1
+
+  401007:	48 83 c4 08          	add    $0x8,%rsp
+  40100b:	c3                   	ret                                 # ret range (eax)
+
+
+# all caller saved
+# range --- eax
+# left --- esi
+# right --- edx
+# input --- rdi (constant)