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1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py2;3; Verify that snprintf calls with a constant size not exceeding INT_MAX4; and a "%c" format string are transformed into a store of the character.5; Also verify that a size in excess of INT_MAX prevents the transformation.6;7; RUN: opt < %s -passes=instcombine -S | FileCheck %s8 9@pcnt_c = constant [3 x i8] c"%c\00"10 11@adst = external global [0 x ptr]12@asiz = external global [0 x i32]13 14declare i32 @snprintf(ptr, i64, ptr, ...)15 16 17; Verify that all snprintf calls with a bound between INT_MAX and down18; to 0 are transformed to memcpy.19 20define void @fold_snprintf_pcnt_c(i32 %c) {21; CHECK-LABEL: @fold_snprintf_pcnt_c(22; CHECK-NEXT: [[PDIMAX:%.*]] = load ptr, ptr @adst, align 823; CHECK-NEXT: store i8 1, ptr [[PDIMAX]], align 124; CHECK-NEXT: [[NUL:%.*]] = getelementptr inbounds nuw i8, ptr [[PDIMAX]], i64 125; CHECK-NEXT: store i8 0, ptr [[NUL]], align 126; CHECK-NEXT: store i32 1, ptr @asiz, align 427; CHECK-NEXT: [[PD2:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 8), align 828; CHECK-NEXT: store i8 2, ptr [[PD2]], align 129; CHECK-NEXT: [[NUL1:%.*]] = getelementptr inbounds nuw i8, ptr [[PD2]], i64 130; CHECK-NEXT: store i8 0, ptr [[NUL1]], align 131; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 4), align 432; CHECK-NEXT: [[PD2_0:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 16), align 833; CHECK-NEXT: store i8 0, ptr [[PD2_0]], align 134; CHECK-NEXT: [[NUL2:%.*]] = getelementptr inbounds nuw i8, ptr [[PD2_0]], i64 135; CHECK-NEXT: store i8 0, ptr [[NUL2]], align 136; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 8), align 437; CHECK-NEXT: [[PD1:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 24), align 838; CHECK-NEXT: store i8 0, ptr [[PD1]], align 139; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 12), align 440; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 16), align 441; CHECK-NEXT: [[PD2_C:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 32), align 842; CHECK-NEXT: [[CHAR:%.*]] = trunc i32 [[C:%.*]] to i843; CHECK-NEXT: store i8 [[CHAR]], ptr [[PD2_C]], align 144; CHECK-NEXT: [[NUL3:%.*]] = getelementptr inbounds nuw i8, ptr [[PD2_C]], i64 145; CHECK-NEXT: store i8 0, ptr [[NUL3]], align 146; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 16), align 447; CHECK-NEXT: [[PD1_C:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 40), align 848; CHECK-NEXT: store i8 0, ptr [[PD1_C]], align 149; CHECK-NEXT: store i32 1, ptr getelementptr (i8, ptr @asiz, i64 20), align 450; CHECK-NEXT: ret void51;52 53 ; Transform snprintf(dst, INT_MAX, "%c", 1) to memcpy(dst, "1", 2), 1.54 %pdimax = load ptr, ptr @adst55 %nimax = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pdimax, i64 2147483647, ptr @pcnt_c, i32 1)56 store i32 %nimax, ptr @asiz57 58 ; Transform snprintf(dst, 2, "%c", '\2') to memcpy(dst, "2", 2), 1.59 %pd2 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 1)60 %n2 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd2, i64 2, ptr @pcnt_c, i8 2)61 store i32 %n2, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 1)62 63 ; Transform snprintf(dst, 2, "%c", '\0') to memcpy(dst, "\0", 2), 1.64 %pd2_0 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 2)65 %n2_0 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd2_0, i64 2, ptr @pcnt_c, i8 0)66 store i32 %n2_0, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 2)67 68 ; Transform snprintf(dst, 1, "%c", (short)3) to memcpy(dst, "\3", 2), 1.69 %pd1 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 3)70 %n1 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd1, i64 1, ptr @pcnt_c, i16 3)71 store i32 %n1, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 3)72 73 ; Fold snprintf(dst, 0, "%c", 4) to 1.74 %pd0 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 4)75 %n0 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd0, i64 0, ptr @pcnt_c, i32 4)76 store i32 %n0, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 4)77 78 79 ; Transform snprintf(dst, 2, "%c", c) with a nonconstant c to80 ; dst[0] = c, dst[1] = '\0', 1.81 %pd2_c = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 4)82 %n2_c = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd2_c, i64 2, ptr @pcnt_c, i32 %c)83 store i32 %n2_c, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 4)84 85 ; Transform snprintf(dst, 1, "%c", c) with a nonconstant c to *dst = '\0', 0.86 %pd1_c = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 5)87 %n1_c = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pd1_c, i64 1, ptr @pcnt_c, i32 %c)88 store i32 %n1_c, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 5)89 90 ret void91}92 93 94; Verify that snprintf calls with a bound greater than INT_MAX are not95; transformed. POSIX requires implementations to set errno to EOVERFLOW96; so such calls could be folded to just that followed by returning -1.97 98define void @call_snprintf_pcnt_c_ximax(i32 %c) {99; CHECK-LABEL: @call_snprintf_pcnt_c_ximax(100; CHECK-NEXT: [[PDM1:%.*]] = load ptr, ptr @adst, align 8101; CHECK-NEXT: [[NM1:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr noundef nonnull dereferenceable(1) [[PDM1]], i64 -1, ptr nonnull @pcnt_c, i8 0)102; CHECK-NEXT: store i32 [[NM1]], ptr @asiz, align 4103; CHECK-NEXT: [[PDIMAXP1:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 8), align 8104; CHECK-NEXT: [[NIMAXP1:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr noundef nonnull dereferenceable(1) [[PDIMAXP1]], i64 2147483648, ptr nonnull @pcnt_c, i8 1)105; CHECK-NEXT: store i32 [[NIMAXP1]], ptr getelementptr (i8, ptr @asiz, i64 4), align 4106; CHECK-NEXT: [[PDM1SL32:%.*]] = load ptr, ptr getelementptr (i8, ptr @adst, i64 16), align 8107; CHECK-NEXT: [[NM1SL32:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr noundef nonnull dereferenceable(1) [[PDM1SL32]], i64 -4294967296, ptr nonnull @pcnt_c, i8 1)108; CHECK-NEXT: store i32 [[NM1SL32]], ptr getelementptr (i8, ptr @asiz, i64 8), align 4109; CHECK-NEXT: ret void110;111 112 %pdm1 = load ptr, ptr @adst113 %nm1 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pdm1, i64 -1, ptr @pcnt_c, i8 0)114 store i32 %nm1, ptr @asiz115 116 117 %pdimaxp1 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 1)118 %nimaxp1 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pdimaxp1, i64 2147483648, ptr @pcnt_c, i8 1)119 store i32 %nimaxp1, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 1)120 121 ; Exercise snprintf(dst, -1LU << 32, "%c", c).122 %pdm1sl32 = load ptr, ptr getelementptr ([0 x ptr], ptr @adst, i32 0, i32 2)123 %nm1sl32 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %pdm1sl32, i64 18446744069414584320, ptr @pcnt_c, i8 1)124 store i32 %nm1sl32, ptr getelementptr ([0 x i32], ptr @asiz, i32 0, i32 2)125 126 ret void127}128