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| author | Richard Henderson <richard.henderson@linaro.org> | 2024-03-26 11:21:38 -1000 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2024-03-29 12:15:55 -1000 |
| commit | 2911e9b95f3bb03783ae5ca3e2494dc3b44a9161 (patch) | |
| tree | c316e248a8843ced44d250823663f6f3f337ae60 /tcg/optimize.c | |
| parent | 889cd5a8e2dd6cf8793faba22fda38b78553ae24 (diff) | |
tcg/optimize: Fix sign_mask for logical right-shift
The 'sign' computation is attempting to locate the sign bit that has
been repeated, so that we can test if that bit is known zero. That
computation can be zero if there are no known sign repetitions.
Cc: qemu-stable@nongnu.org
Fixes: 93a967fbb57 ("tcg/optimize: Propagate sign info for shifting")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2248
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Diffstat (limited to 'tcg/optimize.c')
| -rw-r--r-- | tcg/optimize.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index 752cc5c56b..275db77b42 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -2376,7 +2376,7 @@ static bool fold_shift(OptContext *ctx, TCGOp *op) * will not reduced the number of input sign repetitions. */ sign = (s_mask & -s_mask) >> 1; - if (!(z_mask & sign)) { + if (sign && !(z_mask & sign)) { ctx->s_mask = s_mask; } break; |