diff options
author | Paolo Bonzini | 2022-09-11 14:04:36 +0200 |
---|---|---|
committer | Richard Henderson | 2022-11-15 00:34:42 +0100 |
commit | d1bb978ba1654ddc6e927621b554eebb216fb9dd (patch) | |
tree | 90ee84e4dde9310b4175200161b9db54a8bacdde /tests | |
parent | Merge tag 'pull-target-arm-20221114' of https://git.linaro.org/people/pmaydel... (diff) | |
download | qemu-d1bb978ba1654ddc6e927621b554eebb216fb9dd.tar.gz qemu-d1bb978ba1654ddc6e927621b554eebb216fb9dd.tar.xz qemu-d1bb978ba1654ddc6e927621b554eebb216fb9dd.zip |
target/i386: fix cmpxchg with 32-bit register destination
Unlike the memory case, where "the destination operand receives a write
cycle without regard to the result of the comparison", rm must not be
touched altogether if the write fails, including not zero-extending
it on 64-bit processors. This is not how the movcond currently works,
because it is always followed by a gen_op_mov_reg_v to rm.
To fix it, introduce a new function that is similar to gen_op_mov_reg_v
but writes to a TCG temporary.
Considering that gen_extu(ot, oldv) is not needed in the memory case
either, the two cases for register and memory destinations are different
enough that one might as well fuse the two "if (mod == 3)" into one.
So do that too.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/508
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[rth: Add a test case ]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'tests')
-rw-r--r-- | tests/tcg/x86_64/Makefile.target | 1 | ||||
-rw-r--r-- | tests/tcg/x86_64/cmpxchg.c | 42 |
2 files changed, 43 insertions, 0 deletions
diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target index 6895db1c43..4eac78293f 100644 --- a/tests/tcg/x86_64/Makefile.target +++ b/tests/tcg/x86_64/Makefile.target @@ -11,6 +11,7 @@ include $(SRC_PATH)/tests/tcg/i386/Makefile.target ifeq ($(filter %-linux-user, $(TARGET)),$(TARGET)) X86_64_TESTS += vsyscall X86_64_TESTS += noexec +X86_64_TESTS += cmpxchg TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64 else TESTS=$(MULTIARCH_TESTS) diff --git a/tests/tcg/x86_64/cmpxchg.c b/tests/tcg/x86_64/cmpxchg.c new file mode 100644 index 0000000000..5891735161 --- /dev/null +++ b/tests/tcg/x86_64/cmpxchg.c @@ -0,0 +1,42 @@ +#include <assert.h> + +static int mem; + +static unsigned long test_cmpxchgb(unsigned long orig) +{ + unsigned long ret; + mem = orig; + asm("cmpxchgb %b[cmp],%[mem]" + : [ mem ] "+m"(mem), [ rax ] "=a"(ret) + : [ cmp ] "r"(0x77), "a"(orig)); + return ret; +} + +static unsigned long test_cmpxchgw(unsigned long orig) +{ + unsigned long ret; + mem = orig; + asm("cmpxchgw %w[cmp],%[mem]" + : [ mem ] "+m"(mem), [ rax ] "=a"(ret) + : [ cmp ] "r"(0x7777), "a"(orig)); + return ret; +} + +static unsigned long test_cmpxchgl(unsigned long orig) +{ + unsigned long ret; + mem = orig; + asm("cmpxchgl %[cmp],%[mem]" + : [ mem ] "+m"(mem), [ rax ] "=a"(ret) + : [ cmp ] "r"(0x77777777u), "a"(orig)); + return ret; +} + +int main() +{ + unsigned long test = 0xdeadbeef12345678ull; + assert(test == test_cmpxchgb(test)); + assert(test == test_cmpxchgw(test)); + assert(test == test_cmpxchgl(test)); + return 0; +} |