add launchpad bug reports without comments

1 files changed, 102 insertions, 0 deletions

diff --git a/results/scraper/launchpad-without-comments/1843205 b/results/scraper/launchpad-without-comments/1843205
new file mode 100644
index 00000000..c7792917
--- /dev/null
+++ b/results/scraper/launchpad-without-comments/1843205
@@ -0,0 +1,102 @@
+Inaccurate Fmod on i386
+
+# Qemu Version
+
+```bash
+$ qemu-i386 --version
+qemu-i386 version 3.0.1 (qemu-3.0.1-4.fc29)
+Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers
+```
+
+# Failing Source Code (C)
+
+```c
+#include <math.h>
+#include <stdio.h>
+
+int main()
+{
+    double x = 29860476080414620.0;
+    double y = 17.0;
+    double z = fmod(x, y);
+    printf("%f\n", z);
+    return 0;
+}
+```
+
+The code was compiled with GCC (8.3.1) on x86-64 with the flags `-O3 -m32 -lm -static`.
+
+# Emitted (Annotated) Assembly
+
+In order to facilitate debugging the issue, the following assembly was generated to show nothing unusual occurred during compilation. The assembly was generated with flags `-S -O3 -m32 -lm`, and then annotated to show the operands to fmod.
+
+```asm
+	.file	"a.c"
+	.text
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC2:
+	.string	"%f\n"
+	.section	.text.startup,"ax",@progbits
+	.p2align 4,,15
+	.globl	main
+	.type	main, @function
+main:
+.LFB16:
+	.cfi_startproc
+	leal	4(%esp), %ecx
+	.cfi_def_cfa 1, 0
+	andl	$-16, %esp
+	pushl	-4(%ecx)
+	pushl	%ebp
+	.cfi_escape 0x10,0x5,0x2,0x75,0
+	movl	%esp, %ebp
+	pushl	%ecx
+	.cfi_escape 0xf,0x3,0x75,0x7c,0x6
+	subl	$4, %esp
+	pushl	$1076953088				; high 32-bits of double for y
+	pushl	$0 						; low 32-bits of double for y
+	pushl	$1130005884				; high 32-bits of double for x
+	pushl	$2003187687				; low 32-bits of double for x
+	call	fmod
+	movl	$.LC2, (%esp)
+	fstpl	4(%esp)
+	call	printf
+	movl	-4(%ebp), %ecx
+	.cfi_def_cfa 1, 0
+	addl	$16, %esp
+	xorl	%eax, %eax
+	leave
+	.cfi_restore 5
+	leal	-4(%ecx), %esp
+	.cfi_def_cfa 4, 4
+	ret
+	.cfi_endproc
+.LFE16:
+	.size	main, .-main
+	.ident	"GCC: (GNU) 8.3.1 20190223 (Red Hat 8.3.1-2)"
+	.section	.note.GNU-stack,"",@progbits
+```
+
+# Result
+
+Running the compiled binary on x86_64 produces the expected value of `15.000000`, while using `qemu-i386 <binary>` produces the unexpected result of `-4.000000`.
+
+This was tested against:
+
+1. Qemu 3.0.1 for Fedora 29.
+2. Qemu 4.1.0 built from source, downloaded from https://download.qemu.org/qemu-4.1.0.tar.xz
+3. Qemu built-from-source against commit 90b1e3afd33226b6078fec6d77a18373712a975c.
+
+# Building Qemu
+
+Qemu built-from-source was compiled as follows:
+
+```bash
+mkdir build && cd build
+../configure --disable-kvm --target-list="i386-linux-user"
+make -j 5
+```
+
+# Results
+
+All built versions of Qemu running the 32-bit failed to produce the accurate result. Using qemu-x86_64 against an x86_64 binary built from the same C source code produces correct results. Running the 32-bit binary natively produces the correct result.
\ No newline at end of file