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target/s390x: Fix determination of overflow condition code after addition
This program currently prints different results when run with TCG instead of running on real s390x hardware: #include <stdio.h> int overflow_32 (int x, int y) { int sum; return ! __builtin_add_overflow (x, y, &sum); } int overflow_64 (long long x, long long y) { long sum; return ! __builtin_add_overflow (x, y, &sum); } int a1 = -2147483648; int b1 = -2147483648; long long a2 = -9223372036854775808L; long long b2 = -9223372036854775808L; int main () { { int a = a1; int b = b1; printf ("a = 0x%x, b = 0x%x\n", a, b); printf ("no_overflow = %d\n", overflow_32 (a, b)); } { long long a = a2; long long b = b2; printf ("a = 0x%llx, b = 0x%llx\n", a, b); printf ("no_overflow = %d\n", overflow_64 (a, b)); } } Signed-off-by: Bruno Haible <bruno@clisp.org> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/616 Message-Id: <20220323162621.139313-2-thuth@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
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@ -136,7 +136,7 @@ static uint32_t cc_calc_subu(uint64_t borrow_out, uint64_t result)
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static uint32_t cc_calc_add_64(int64_t a1, int64_t a2, int64_t ar)
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{
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if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
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if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) {
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return 3; /* overflow */
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} else {
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if (ar < 0) {
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@ -196,7 +196,7 @@ static uint32_t cc_calc_comp_64(int64_t dst)
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static uint32_t cc_calc_add_32(int32_t a1, int32_t a2, int32_t ar)
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{
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if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
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if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) {
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return 3; /* overflow */
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} else {
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if (ar < 0) {
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