[PATCH v2 4/5] target/s390x: Fix shifting 32-bit values for more than 31 bits

[Ilya Leoshkevich]

According to PoP, both 32- and 64-bit shifts use lowest 6 address
bits. The current code special-cases 32-bit shifts to use only 5 bits,
which is not correct. For example, shifting by 32 bits currently
preserves the initial value, however, it's supposed zero it out
instead.

Fix by merging sh32 and sh64 and adapting cc_calc_sla_32() to shift
values greater than 31.

Fixes: cbe24bfa91d2 ("target-s390: Convert SHIFT, ROTATE SINGLE")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 target/s390x/tcg/cc_helper.c   | 32 +++++-------------------------
 target/s390x/tcg/insn-data.def | 36 +++++++++++++++++-----------------
 target/s390x/tcg/translate.c   | 31 ++++++++++-------------------
 3 files changed, 33 insertions(+), 66 deletions(-)

diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c
index b6acffa3e8..3cfbfadf48 100644
--- a/target/s390x/tcg/cc_helper.c
+++ b/target/s390x/tcg/cc_helper.c
@@ -268,33 +268,6 @@ static uint32_t cc_calc_icm(uint64_t mask, uint64_t val)
     }
 }
 
-static uint32_t cc_calc_sla_32(uint32_t src, int shift)
-{
-    uint32_t mask = ((1U << shift) - 1U) << (32 - shift);
-    uint32_t sign = 1U << 31;
-    uint32_t match;
-    int32_t r;
-
-    /* Check if the sign bit stays the same.  */
-    if (src & sign) {
-        match = mask;
-    } else {
-        match = 0;
-    }
-    if ((src & mask) != match) {
-        /* Overflow.  */
-        return 3;
-    }
-
-    r = ((src << shift) & ~sign) | (src & sign);
-    if (r == 0) {
-        return 0;
-    } else if (r < 0) {
-        return 1;
-    }
-    return 2;
-}
-
 static uint32_t cc_calc_sla_64(uint64_t src, int shift)
 {
     /* Do not use (1ULL << (shift + 1)): it triggers UB when shift is 63.  */
@@ -323,6 +296,11 @@ static uint32_t cc_calc_sla_64(uint64_t src, int shift)
     return 2;
 }
 
+static uint32_t cc_calc_sla_32(uint32_t src, int shift)
+{
+    return cc_calc_sla_64(((uint64_t)src) << 32, shift);
+}
+
 static uint32_t cc_calc_flogr(uint64_t dst)
 {
     return dst ? 2 : 0;
diff --git a/target/s390x/tcg/insn-data.def b/target/s390x/tcg/insn-data.def
index 90c753068c..1c3e115712 100644
--- a/target/s390x/tcg/insn-data.def
+++ b/target/s390x/tcg/insn-data.def
@@ -747,8 +747,8 @@
     C(0xb9e1, POPCNT,  RRE,   PC,  0, r2_o, r1, 0, popcnt, nz64)
 
 /* ROTATE LEFT SINGLE LOGICAL */
-    C(0xeb1d, RLL,     RSY_a, Z,   r3_o, sh32, new, r1_32, rll32, 0)
-    C(0xeb1c, RLLG,    RSY_a, Z,   r3_o, sh64, r1, 0, rll64, 0)
+    C(0xeb1d, RLL,     RSY_a, Z,   r3_o, sh, new, r1_32, rll32, 0)
+    C(0xeb1c, RLLG,    RSY_a, Z,   r3_o, sh, r1, 0, rll64, 0)
 
 /* ROTATE THEN INSERT SELECTED BITS */
     C(0xec55, RISBG,   RIE_f, GIE, 0, r2, r1, 0, risbg, s64)
@@ -784,29 +784,29 @@
     C(0x0400, SPM,     RR_a,  Z,   r1, 0, 0, 0, spm, 0)
 
 /* SHIFT LEFT SINGLE */
-    D(0x8b00, SLA,     RS_a,  Z,   r1, sh32, new, r1_32, sla, 0, 31)
-    D(0xebdd, SLAK,    RSY_a, DO,  r3, sh32, new, r1_32, sla, 0, 31)
-    D(0xeb0b, SLAG,    RSY_a, Z,   r3, sh64, r1, 0, sla, 0, 63)
+    D(0x8b00, SLA,     RS_a,  Z,   r1, sh, new, r1_32, sla, 0, 31)
+    D(0xebdd, SLAK,    RSY_a, DO,  r3, sh, new, r1_32, sla, 0, 31)
+    D(0xeb0b, SLAG,    RSY_a, Z,   r3, sh, r1, 0, sla, 0, 63)
 /* SHIFT LEFT SINGLE LOGICAL */
-    C(0x8900, SLL,     RS_a,  Z,   r1_o, sh32, new, r1_32, sll, 0)
-    C(0xebdf, SLLK,    RSY_a, DO,  r3_o, sh32, new, r1_32, sll, 0)
-    C(0xeb0d, SLLG,    RSY_a, Z,   r3_o, sh64, r1, 0, sll, 0)
+    C(0x8900, SLL,     RS_a,  Z,   r1_o, sh, new, r1_32, sll, 0)
+    C(0xebdf, SLLK,    RSY_a, DO,  r3_o, sh, new, r1_32, sll, 0)
+    C(0xeb0d, SLLG,    RSY_a, Z,   r3_o, sh, r1, 0, sll, 0)
 /* SHIFT RIGHT SINGLE */
-    C(0x8a00, SRA,     RS_a,  Z,   r1_32s, sh32, new, r1_32, sra, s32)
-    C(0xebdc, SRAK,    RSY_a, DO,  r3_32s, sh32, new, r1_32, sra, s32)
-    C(0xeb0a, SRAG,    RSY_a, Z,   r3_o, sh64, r1, 0, sra, s64)
+    C(0x8a00, SRA,     RS_a,  Z,   r1_32s, sh, new, r1_32, sra, s32)
+    C(0xebdc, SRAK,    RSY_a, DO,  r3_32s, sh, new, r1_32, sra, s32)
+    C(0xeb0a, SRAG,    RSY_a, Z,   r3_o, sh, r1, 0, sra, s64)
 /* SHIFT RIGHT SINGLE LOGICAL */
-    C(0x8800, SRL,     RS_a,  Z,   r1_32u, sh32, new, r1_32, srl, 0)
-    C(0xebde, SRLK,    RSY_a, DO,  r3_32u, sh32, new, r1_32, srl, 0)
-    C(0xeb0c, SRLG,    RSY_a, Z,   r3_o, sh64, r1, 0, srl, 0)
+    C(0x8800, SRL,     RS_a,  Z,   r1_32u, sh, new, r1_32, srl, 0)
+    C(0xebde, SRLK,    RSY_a, DO,  r3_32u, sh, new, r1_32, srl, 0)
+    C(0xeb0c, SRLG,    RSY_a, Z,   r3_o, sh, r1, 0, srl, 0)
 /* SHIFT LEFT DOUBLE */
-    D(0x8f00, SLDA,    RS_a,  Z,   r1_D32, sh64, new, r1_D32, sla, 0, 63)
+    D(0x8f00, SLDA,    RS_a,  Z,   r1_D32, sh, new, r1_D32, sla, 0, 63)
 /* SHIFT LEFT DOUBLE LOGICAL */
-    C(0x8d00, SLDL,    RS_a,  Z,   r1_D32, sh64, new, r1_D32, sll, 0)
+    C(0x8d00, SLDL,    RS_a,  Z,   r1_D32, sh, new, r1_D32, sll, 0)
 /* SHIFT RIGHT DOUBLE */
-    C(0x8e00, SRDA,    RS_a,  Z,   r1_D32, sh64, new, r1_D32, sra, s64)
+    C(0x8e00, SRDA,    RS_a,  Z,   r1_D32, sh, new, r1_D32, sra, s64)
 /* SHIFT RIGHT DOUBLE LOGICAL */
-    C(0x8c00, SRDL,    RS_a,  Z,   r1_D32, sh64, new, r1_D32, srl, 0)
+    C(0x8c00, SRDL,    RS_a,  Z,   r1_D32, sh, new, r1_D32, srl, 0)
 
 /* SQUARE ROOT */
     F(0xb314, SQEBR,   RRE,   Z,   0, e2, new, e1, sqeb, 0, IF_BFP)
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index 68ca7e476a..5a2b609d0f 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -1178,19 +1178,6 @@ struct DisasInsn {
 /* ====================================================================== */
 /* Miscellaneous helpers, used by several operations.  */
 
-static void help_l2_shift(DisasContext *s, DisasOps *o, int mask)
-{
-    int b2 = get_field(s, b2);
-    int d2 = get_field(s, d2);
-
-    if (b2 == 0) {
-        o->in2 = tcg_const_i64(d2 & mask);
-    } else {
-        o->in2 = get_address(s, 0, b2, d2);
-        tcg_gen_andi_i64(o->in2, o->in2, mask);
-    }
-}
-
 static DisasJumpType help_goto_direct(DisasContext *s, uint64_t dest)
 {
     if (dest == s->pc_tmp) {
@@ -5923,17 +5910,19 @@ static void in2_ri2(DisasContext *s, DisasOps *o)
 }
 #define SPEC_in2_ri2 0
 
-static void in2_sh32(DisasContext *s, DisasOps *o)
+static void in2_sh(DisasContext *s, DisasOps *o)
 {
-    help_l2_shift(s, o, 31);
-}
-#define SPEC_in2_sh32 0
+    int b2 = get_field(s, b2);
+    int d2 = get_field(s, d2);
 
-static void in2_sh64(DisasContext *s, DisasOps *o)
-{
-    help_l2_shift(s, o, 63);
+    if (b2 == 0) {
+        o->in2 = tcg_const_i64(d2 & 0x3f);
+    } else {
+        o->in2 = get_address(s, 0, b2, d2);
+        tcg_gen_andi_i64(o->in2, o->in2, 0x3f);
+    }
 }
-#define SPEC_in2_sh64 0
+#define SPEC_in2_sh 0
 
 static void in2_m2_8u(DisasContext *s, DisasOps *o)
 {
-- 
2.31.1