[PULL,01/46] tcg/s390: Fix compare instruction from extended-immediate facility

Commit Message

Richard Henderson Feb. 5, 2021, 10:56 p.m. UTC

From: Philippe Mathieu-Daudé <[e-mail]>

The code is currently comparing c2 to the type promotion of
uint32_t and int32_t. That is, the conversion rules are as:

  (common_type) c2 == (common_type) (uint32_t)
                        (is_unsigned
                        ? (uint32_t)c2
                        : (uint32_t)(int32_t)c2)

In the signed case we lose the desired sign extensions because
of the argument promotion rules of the ternary operator.

Solve the problem by doing the round-trip parsing through the
intermediate type and back to the desired common type (all at
one expression).

Fixes: a534bb15f30 ("tcg/s390: Use constant pool for cmpi")
Tested-by: Richard W.M. Jones <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Reported-by: Miroslav Rezanina <[e-mail]>
Reported-by: Richard W.M. Jones <[e-mail]>
Suggested-by: David Hildenbrand <[e-mail]>
Suggested-by: Eric Blake <[e-mail]>
Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Richard Henderson <[e-mail]>
---
 tcg/s390/tcg-target.c.inc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/tcg/s390/tcg-target.c.inc b/tcg/s390/tcg-target.c.inc
index b67470137c..695d7ee652 100644
--- a/tcg/s390/tcg-target.c.inc
+++ b/tcg/s390/tcg-target.c.inc
@@ -1067,7 +1067,7 @@  static int tgen_cmp(TCGContext *s, TCGType type, TCGCond c, TCGReg r1,
                 op = (is_unsigned ? RIL_CLFI : RIL_CFI);
                 tcg_out_insn_RIL(s, op, r1, c2);
                 goto exit;
-            } else if (c2 == (is_unsigned ? (uint32_t)c2 : (int32_t)c2)) {
+            } else if (c2 == (is_unsigned ? (TCGArg)(uint32_t)c2 : (TCGArg)(int32_t)c2)) {
                 op = (is_unsigned ? RIL_CLGFI : RIL_CGFI);
                 tcg_out_insn_RIL(s, op, r1, c2);
                 goto exit;