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authorRichard Henderson2022-02-17 02:06:22 +0100
committerRichard Henderson2022-02-28 19:04:06 +0100
commit8929906e212cbe606e361cbd32917dcbe5bb6dd0 (patch)
tree4acc52416554ce423d8cb93f7cc303affa7303a8 /target/m68k
parentMerge remote-tracking branch 'remotes/shorne/tags/or1k-pull-request' into sta... (diff)
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tcg: Remove dh_alias indirection for dh_typecode
The dh_alias redirect is intended to handle TCG types as distinguished from C types. TCG does not distinguish signed int from unsigned int, because they are the same size. However, we need to retain this distinction for dh_typecode, lest we fail to extend abi types properly for the host call parameters. This bug was detected when running the 'arm' emulator on an s390 system. The s390 uses TCG_TARGET_EXTEND_ARGS which triggers code in tcg_gen_callN to extend 32 bit values to 64 bits; the incorrect sign data in the typemask for each argument caused the values to be extended as unsigned values. This simple program exhibits the problem: static volatile int num = -9; static volatile int den = -5; int main(void) { int quo = num / den; printf("num %d den %d quo %d\n", num, den, quo); exit(0); } When run on the broken qemu, this results in: num -9 den -5 quo 0 The correct result is: num -9 den -5 quo 1 Fixes: 7319d83a735 ("tcg: Combine dh_is_64bit and dh_is_signed to dh_typecode") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/876 Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com> Tested-by: Keith Packard <keithp@keithp.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'target/m68k')
-rw-r--r--target/m68k/helper.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/target/m68k/helper.h b/target/m68k/helper.h
index 9842eeaa95..0a6b4146f6 100644
--- a/target/m68k/helper.h
+++ b/target/m68k/helper.h
@@ -17,6 +17,7 @@ DEF_HELPER_4(cas2l_parallel, void, env, i32, i32, i32)
#define dh_alias_fp ptr
#define dh_ctype_fp FPReg *
+#define dh_typecode_fp dh_typecode_ptr
DEF_HELPER_3(exts32, void, env, fp, s32)
DEF_HELPER_3(extf32, void, env, fp, f32)